Polymerization of, and depolymerization to, cyclic ethers using selected metal compound catalysts

ABSTRACT

A process for polymerizing oxiranes, oxetanes, oxepanes, dioxolanes, trioxanes, and tetrahydrofurans to their respective polymers by contacting them with a selected metal compound is disclosed; and also a process for depolymerizing polytetrahydrofurans to monomeric tetrahydrofurans by contacting the polymer with a selected metal compound at a temperature of about 100° C. to about 250° C. The catalysts may be in solution or part of a heterogeneous solid, and selected organic compounds are used as accelerators in the polymerizations. The polymeric products, some of which are novel, may be used as polyether monomers for further polymerization, as by reaction with isocyanates to produce polyurethanes, and other useful polymers. Some of the polymeric products are relatively high in molecular weight and are suitable for direct use, for instance as spandex fibers.

This is a continuation of application Ser. No. 08/424,675, filed Apr.19, 1995, now U.S. Pat. No. 5,635,585, which in turn is a division ofSer. No. 08/283,108 filed Jul. 29, 1994, now abandoned; which is, inturn, a continuation-in-part of Ser. No. 08/198,024 filed Feb. 17, 1994,now abandoned; Ser. No. 08/141,160 filed Oct. 21, 1993, now abandoned;PCT/US93/09808 filed Oct. 20, 1993; Ser. No. 08/093,243 filed Jul. 16,1993, now abandoned; Ser. No. 08/093,119 filed Jul. 16, 1993, nowabandoned; Ser. No. 08/021,368 filed Feb. 23, 1993, now abandoned; andSer. No. 07/964,313 filed Oct. 21, 1992, now abandoned.

FIELD OF THE INVENTION

This invention concerns the polymerization of oxiranes, oxetanes,oxepanes, 1,13-dioxolanes, 1,3,5-trioxanes, and tetrahydrofurans tolinear polyethers, and the depolymerization of polytetrahydrofurans totetrahydrofurans, both catalyzed by selected metal compounds. Thecatalysts may be in solution or part of a heterogeneous solid, andselected organic compounds are used as accelerators in thepolymerizations. Novel polymeric products are produced in some of thepolymerizations.

BACKGROUND OF THE INVENTION

Cyclic ethers are polymerized by various means to give products ofwidespread utility. For instance, ethylene oxide is polymerized topolyethylene oxide which is useful, in lower molecular weight grades,for ceramics (as a binder), cosmetics, lubricants, polyurethanes; and inhigher molecular weight grades, for packaging film, denture adhesives,lubricants, flocculation and for other articles and products.Tetrahydrofuran (THF) is polymerized to poly(tetramethylene ether)glycol which is useful in the preparation of Spandex fibers;polyurethane resins which are useful in elastomeric parts; andthermoplastic elastomers which are useful for molding various mechanicalparts. Therefore, improved methods of making these polymers are sought.Also useful are methods of depolymerizing the polyethers to usefulproducts, such as the cyclic ethers from which they were originallymade. Such depolymerizations allow for the recycle of off specificationor used polyethers to useful products such as polyethers, therebyreducing waste.

Block copolymers, of polytetrahydrofurans (usually as the diols) andpolyesters or poly(urea-urethanes) are commonly used in commercialproducts, such as thermoplastic elastomers (Hytrel® thermoplasticelastomer), spandex fibers (Lycra® spandex fiber) and urethane rubbers(Adiprene® urethane rubber). The usual procedure in making theseproducts is to combine a polyether diol with suitable reactants, such asester segment forming compounds, or urea and/or urethane formingcompounds such as amines and/or diols with diisocyanates. Improvedmethods of making such commercially important polymers are sought by theartisan.

U.S. Pat No. 3,842,019 describes the polymerization of oxiranes andother small ring compounds by a presumed cationic mechanism, using asthe catalyst the decomposition products of metalperfluoroalkylsulfonates. These catalysts are described as "latent",that is no reaction occurs until the metal salt is decomposed. Thereactions reported are relatively slow, even at elevated temperatures.

U.S. Pat. Nos. 5,084,586 and 5,124,417 describe the cationicpolymerization of various monomers, including cyclic ethers, using oniumcations, whose corresponding anions are fluoroalkylsulfatometallates.Onium ion catalyzed cationic polymerizations are well known, and thereis no mention in these patents of the use of metal salts not containingonium ions, such as metal triflates, as catalysts for the polymerizationof cyclic ethers.

Japanese Patent Application 51-82397 describes the polymerization oftetrahydrofuran using a combination of fluorosulfonic acid and acarboxylic acid as catalysts. No mention is made of metal salts, such ametal triflates as catalysts.

J. S. Hrkach, et al., Macromolecules, vol. 23, p. 4042-4046 (1990)describe the polymerization of tetrahydrofuran using trimethylsilyltrifluoromethanesulfonate as the initiator. No mention is made of anyother triflates as catalysts for this polymerization.

German Patent Application 2,459,163 describes the polymerization of THFusing a combination of ferric chloride and carboxylic anhydride ascatalyst.

G. A. Olah, et al., J. Appl. Polym. Sci., Vol. 45, 1355-1360 (1992)describe the use of boron, aluminum and gallium tristriflate to catalyzethe polymerization of THF.

S. L. Borkowsky, et al., Organometal., Vol. 10, p. 1268-1274 (1991)report that certain zirconium tetrahydrofuran. No mention is made ofzirconium perfluoroalkylsulfonates, or of copolymers.

T. Misaki, et al., Nippon Kagaku Kaishi, p. 168-174 (1973) report on thepolymerization of THF using a combination of metal aceylacetonates andacetyl chloride.

U.S. Pat. No. 4,303,782 describes the use of zeolites to catalyze thepolymerization of tetrahydrofuran. These polymerization appear toproceed very slowly.

SUMMARY OF THE INVENTION

This invention concerns a first process for the polymerization of cyclicethers, comprising, contacting at a temperature of about -80° C. toabout 150° C. one or more oxiranes, oxetanes, tetrahydrofurans,oxepanes, 1,3-dioxolanes or 1,3,5-trioxanes with a catalyst systemconsisting essentially of a compound of the formula MZ_(s).Q_(t), and anaccelerator selected from the group consisting of carboxylic acids whosepKa in water is less than 6, carboxylic anhydrides and acyl halides,wherein:

M is a metal selected from the group consisting of cobalt, vanadium,copper, mischmetall, niobium, tungsten, strontium, barium, scandium,yttrium, the rare earth metals, titanium, zirconium, hafnium, chromium,molybdenum, tantalum, rhenium, iron, ruthenium, osmium, rhodium,iridium, palladium, platinum, gold, zinc, cadmium, mercury, aluminum,gallium, indium, thulium, germanium, tin, lead, arsenic, antimony andbismuth;

at least one of Z is an anion of the formula R⁵ SO₃ , wherein R⁵ isperfluoroalkyl containing 1 to 12 carbon atoms or part of a fluorinatedpolymer wherein the carbon atoms alpha and beta to the sulfonate groupare together bonded to at least four fluorine atoms, ortetraphenylborate, and the remainder of Z is oxo or one germanium, tin,lead, arsenic, antimony and bismuth;

s is 2 when M is strontium, barium, cobalt, rhodium, copper, iridium,palladium, platinum, chromium, zinc, cadmium or mercury;

s is 3 when M is scandium, yttrium, a rare earth metal, arsenic,antimony, bismuth, gold, iron, ruthenium, mischmetall, osmium, aluminum,gallium, indium or thulium;

s is 4 when M is titanium, zirconium, hafnium, molybdenum, germanium,tin, or lead;

s is 5 when M is rhenium, vanadium, niobium or tantalum;

s is 6 when M is tungsten;

Q is a neutral ligand;

t is 0 or an integer of 1 to 6; and

provided that each oxo group present counts as two of s.

This invention also involves a first process for the depolymerization ofa polyether to a tetrahydrofuran, comprising, contacting at atemperature of about 100° C. to about 250° C., a polymer consistingessentially of one or more repeat units of the formula

    -- CHR.sup.1 CR.sup.2 R.sup.3 CR.sup.2 R.sup.3 CHR.sup.4 O!--

with a compound of the formula MZ₃.Q_(t), wherein:

each R¹, R², R³ and R⁴ is independently hydrogen or hydrocarbylcontaining 1 to 20 carbon atoms;

M is a metal selected from the group consisting of cobalt, vanadium,copper, mischmetall, niobium, tungsten, strontium, barium, scandium,yttrium, the rare earth metals, titanium, zirconium, hafnium, chromium,molybdenum, tantalum, rhenium, iron, ruthenium, osmium, rhodium,iridium, palladium, platinum, silver, gold, zinc, cadmium, mercury,aluminum, gallium, indium, thulium, silicon, germanium, tin, lead,arsenic, antimony and bismuth;

at least one of Z is an anion of the formula R⁵ SO₃ , wherein R⁵ isperfluoroalkyl containing 1 to 12 carbon atoms or part of a fluorinatedpolymer wherein the carbon atoms alpha and beta to the sulfonate groupare together bonded to at least four fluorine atoms, ortetraphenylborate, and the remainder of Z is oxo or one or moremonovalent anions;

s is 1 when M is silver;

s is 2 when M is strontium, barium, cobalt, rhodium, copper, iridium,palladium, platinum, chromium, zinc, cadmium or mercury;

s is 3 when M is scandium, yttrium, a rare earth metal, arsenic,antimony, bismuth, gold, iron, ruthenium, mischmetall, osmium, aluminum,gallium, indium or thulium;

s is 4 when M is titanium, zirconium, hafnium, molybdenum, silicon,germanium, tin, or lead;

s is 5 when M is rhenium, vanadium, niobium or tantalum;

s is 6 when M is tungsten;

Q is a neutral ligand;

t is 0 or an integer of 1 to 6;

and provided that each oxo group present counts as two of s.

This invention also concerns a second process for the polymerization ofcyclic ethers, comprising, contacting one, at a temperature of about-80° C. to about 130° C., or more oxiranes, oxetanes, tetrahydrofurans,oxepanes, 1,3-dioxolanes, or 1,3,5-trioxanes; with a zeolite whichcontains a metal cation selected from the group consisting of strontium,vanadium, copper, mischmetall, niobium, tungsten, cobalt, barium,scandium, yttrium, the rare earth metals, titanium, zirconium, hafnium,chromium, molybdenum, tantalum, rhenium, iron, ruthenium, osmium,rhodium, iridium, palladium, platinum, silver, gold, zinc, cadmium,mercury, aluminum, gallium, indium, group consisting of strontium,vanadium, niobium, bismuth; and an accelerator selected from the groupconsisting of carboxylic anhydrides, acyl halides and carboxylic acidswhose pKa in water is less than about 6.

This invention also concerns a third process for the polymerization ofcyclic ethers, comprising, contacting, at a temperature of about -80° C.to about 130° C., one or more oxiranes, oxetanes, tetrahydrofurans,oxepanes, 1,3-dioxolanes, or 1,3,5-trioxanes; with a catalytic systemconsisting essentially of a heterogeneous catalyst containing a metalperfluoroalkylsulfonate attached to the surface of said catalyst throughsaid metal, and an accelerator; said metal selected from the groupconsisting of strontium, vanadium, copper, mischmetall, niobium,tungsten, cobalt, barium, scandium, yttrium, the rare earth metals,titanium, zirconium, hafnium, chromium, molybdenum, tantalum, rhenium,iron, ruthenium, osmium, rhodium, iridium, palladium, platinum, gold,zinc, cadmium, mercury, indium, thulium, germanium, tin, lead, arsenic,antimony and bismuth; said accelerator selected from the groupconsisting of carboxylic anhydrides, acyl halides, and carboxylic acidswhose pKa in water is less than about 6.

This invention also concerns a second process for the depolymerizationof a polyether to a tetrahydrofuran, comprising, contacting at atemperature of about 100° C. to about 250° C., a polymer consistingessentially of one or more repeat units of the formula

     --CHR.sup.1 CR.sup.2 R.sup.3 CR.sup.2 R.sup.3 CHR.sup.4 O!--

wherein each R¹, R², R³ and R⁴ is independently hydrogen or hydrocarbylcontaining 1 to 20 carbon atoms, with a heterogeneous catalytic systemconsisting essentially of a catalyst containing a metalperfluoroalkylsulfonate attached to the surface of said catalyst throughsaid metal; said metal selected from the group consisting of strontium,vanadium, copper, mischmetall, niobium, tungsten, cobalt, barium,scandium, yttrium, the rare earthe metals, titanium, zirconium, hafnium,chromium, silver, molybdenum, tantalum, rhenium, iron, ruthenium,osmium, rhodium, iridium, palladium, platinum, silver, gold, zinc,cadmium, mercury, aluminum, gallium, indium, thulium, germanium, tin,lead, arsenic, antimony and bismuth.

This invention also concerns a fourth polymerization process for theproduction of poly(ether-esters), comprising, contacting atetrahydrofuran with a catalyst system consisting essentially of apolycarboxylic acid of the formula A(CO₂ H)_(x) and a catalyst of theformula MZ_(s).Q_(t), wherein:

M is a metal selected from the group consisting of cobalt, tungsten,vanadium, niobium, strontium, barium, scandium, yttrium, the rare earthmetals, titanium, zirconium, hafnium, chromium, molybdenum, tantalum,rhenium, iron, ruthenium, osmium, rhodium, iridium, palladium, platinum,silver, gold, zinc, cadmium, mercury, indium, thulium, germanium, tin,lead, arsenic, antimony and bismuth;

Z is an anion of the formula R⁵ SO₃ , wherein R⁵ is perfluoroalkylcontaining 1 to 12 carbon atoms or part of a fluorinated group whereinthe carbon atoms alpha and beta to the sulfonate group are togetherbonded to at least four fluorine atoms;

s is 1 when M is silver,

s is 2 when M is strontium, barium, cobalt, rhodium, iridium, palladium,platinum, chromium, zinc, cadmium or mercury;

s is 3 when M is scandium, yttrium, a rare earth metal, arsenic,antimony, bismuth, gold, iron, ruthenium, osmium, aluminum, gallium,indium or thulium;

s is 4 when M is titanium, zirconium, hafnium, molybdenum, germanium,tin, or lead;

s is 5 when M is rhenium, vanadium, niobium or tantalum;

s is 6 when M is tungsten;

Q is a neutral ligand;

t is 0 or an integer of 1 to 6; and

each A is independently an organic radical having x free valencies;

each x is independently 2, 3, 4, 5 or 6; and provided that:

A is bound to carboxyl groups through a carbon atom;

said polycarboxylic acid has a pKa of about 6 or less;

said polycarboxylic acid does not by itself catalyze polymerization ofthe tetrahydrofuran; and

the ratio of equivalents of carboxyl groups of said polycarboxylic acidto moles of said catalyst is less than 6.

This invention also concerns a polymer consisting essentially of arepeat unit of the formula

     (--CHR.sup.1 CR.sup.2 R.sup.3 CR.sup.2 R.sup.3 CHR.sup.4 O--).sub.n C(O)AC(O)O--!

wherein:

each R¹, R², R³ and R⁴ is hydrogen or hydrocarbyl containing 1 to 20carbon atoms;

each n is independently an integer of 1 or more;

each A is independently hydrocarbylene or substituted hydrocarbylenecontaining one or more functional groups selected from the groupconsisting of imide, amide, urea and urethane;

and provided that each A is bound to an ester group through a carbonatom.

DETAILS OF THE INVENTION

In the first polymerization process described herein one or more cyclicethers, oxiranes, oxetanes, 1,3-dioxolanes, 1,3,5-trioxanes, ortetrahydrofurans are functional groups selected from the groupconsisting of herein, oxirane (more commonly called epoxide) is hereingiven its usual structure, a saturated three membered ring containingtwo carbon atoms and one oxygen atom. Oxetane is also given its commonmeaning, a saturated four membered ring containing three carbon atomsand one oxygen atom. The term oxepane means a saturated seven memberedring containing six carbon atoms and one oxygen atoms. The term1,3-dioxolane means a saturated five membered ring which contains twooxygen atoms separated by 1 carbon atom. The term 1,3,5-trioxane means asix membered ring containing 3 oxygen atoms in which the oxygen atomsand carbons atoms are alternated. All of these terms include compoundscontaining those ring systems which are substituted with hydrocarbyl orhydrocarbylene groups containing 1 to 20 carbon atoms. Thehydrocarbylene groups may form carbocyclic rings, which includebicyclic, tricyclic, etc., systems. By a hydrocarbylene group herein ismeant a divalent radical containing carbon and hydrogen which is part ofa carbocyclic ring.

Preferred cyclic ethers for the first polymerization have the formula##STR1## wherein n is 2 or 4 and each R¹, R², R³ and R⁴ is independentlyhydrogen or hydrocarbyl containing 1 to 20 carbon atoms. Some of thesecyclic ethers polymerize to give repeat units of the formula -- CHR¹(CR² R³)_(n) CHR⁴ O!--. In a more preferred cyclic ether all of R¹, R²,R³ and R⁴ are hydrogen. In another more preferred cyclic ether wheren=2, R¹, one of R², both of R³ and R⁴ are hydrogen, and the remaining R²is alkyl containing 1-4 carbon atoms, especially preferably theremaining R² is methyl. By hydrocarbyl herein is meant a univalentradical containing carbon and hydrogen.

The first polymerization is run in the presence of an accelerator.Suitable accelerators are carboxylic anhydrides, acyl halides, andcarboxylic acids with a pk_(a) of less than about 6 in water.

By a carboxylic anhydride is meant a compound containing the grouping--C(O)O(O)C--, wherein the free valencies are to other carbon atoms. Apreferred carboxylic anhydride is an anhydride of an alkyl carboxylicacid or a halogen substituted alkyl carboxylic acid, and particularlypreferred anhydrides are acetic anhydride and trifluoroacetic anhydride.

By an acyl halide is meant a compound containing the grouping --C(O)X,where X is chlorine or bromine and the free valence is to another carbonatom. In preferred acyl halides, X is chlorine. Preferred acyl halidesare alkyl acyl halides, and especially preferred are acetyl halides,more preferably acetyl chloride.

By a carboxylic acid is meant a compound containing the grouping--C(O)OH, wherein the free valence is to another carbon atom. Preferredcarboxylic acids have a pKa of less than 5 in water. Useful carboxylicacids include, but are not limited to acetic, trifluoroacetic,chloroacetic, benzoic, trichloroacetic, p-nitrobenzoic, butyric, formic,cyanoacetic, nitropropionic, acrylic, methacrylic, and napthoic acids.Preferred carboxylic acids are trifluoroacetic, acetic, formic,cyanoacetic, nitropropionic, acrylic and methacrylic acids.

When carboxylic anhydride is present one half or more of the end groupsare carboxylic esters. As is known to the artisan, these may behydrolyzed to hydroxyl groups nbyreaction with water, preferably in thepresence of a catalyst, such as a strong acid (sulfuric acid forinstance) or a strong base (such as NaOH). The proportion of acetateends increases the longer the polymerization is allowed to proceed.Although the polymeric diol is often the desired product (it can be usedto make other polymers, such as polyurethanes and polyesters), the halfester or diester is also useful, as in relatively low molecular polymerswhich can be used as solvents.

When an acyl halide is used as the accelerator, the end groups areusually ester on one end, and the halide, X, on the other. Thus thecomplete formula for such a polymer could be X-- CHR¹ (CR² R³)_(n) CHR⁴O!--C(O)Y, where Y is the group to which the acyl group of the acylhalide was bound. Such polymers are useful as intermediates for thepreparation of polymers containing different functional groups. Forexample, the ester may be hydrolyzed to a hydroxyl group, and the halidemay be reacted to form another functional group such as nitrile. If abis(acyl halide), X(O)CYC(O)X, is used as the accelerator, the productof the polymerization will be a polyether with halide (X) end groupswhich contains two internal ester groups, and may have the formula X--CHR¹ (CR² R³)_(n) CHR⁴ O!--C(O)YC(O)-- OCHR¹ (CR² R³)_(n) CHR⁴ !--X.Useful bis(acyl halides) include adipoyl chloride, terephthaloylchloride, and diglycolyl chloride Cl(O)CCH₂ OCH₂ C(O)Cl!.

In the first polymerization when a carboxylic acid is used as theaccelerator, both end groups are usually mostly ester. Thus the completeformula for such a polymer could be Y(O)CO-- CHR¹ (CR² R³)_(n) CHR⁴O)--C(O)Y, where Y is the group to which the acyl group of thecarboxylic acid was bound.

An important consideration in the preparation of polyesters is thenumber average molecular weight (Mn) of the polyether and its molecularweight distribution. When the polyether is to be used as a monomer inthe preparation of another polymer (usually in the diol form), it isoften preferred in the first polymerization that the Mn of the polyetherbe in the range of about 400 to about 20,000, preferably about 500 toabout 5,000.

In the first polymerization the catalyst may be yttrium or rare earthcompound of the formula MZ₃ where M is a trivalent ion of yttrium, orone of the rare earths, lanthanum, cerium, praeseodymium, neodymium,promethium, samarium, europium, gadolinium, terbium, dysprosium,holmium, erbium, thulium, ytterbium, and lutetium.

In the first polymerization preferred metals, M, are strontium, scandiumyttrium, the rare earth metals, titanium, zirconium, hafnium, vanadium,niobium, tantalum, chromium, molybdenum, tungsten, rhenium, iron,ruthenium, palladium, copper, gold, zinc, tin and bismuth. Morepreferred metals are yttrium, the rare earth metals, and scandium.Especially preferred metals are yttrium, ytterbium, dysprosium, erbium,neodymium, lanthanum, and scandium. Another preferred metal is"mischmetall" (sometimes also called "didymium"), which is a mixture ofrare earth metals as obtained from the ore.

It is believed monovalent anions that are relatively nonnucleophilic areuseful as Z. Examples of such anions are tetraphenylborate, R⁵ SO₃ ,wherein R⁵ is perfluoroalkyl, or wherein R⁵ is part of a fluorinatedpolymer wherein the carbon atoms alpha and beta to a sulfonate group aretogether bonded to at least 4 fluorine atoms (as in --CF₂ CF₂ SO₃ ). Itis preferred if R⁵ is perfluoroalkyl. In a particularly preferred R⁵ istrifluoromethyl, and the anion is herein called "triflate".

Generally speaking, in the first polymerization any metallic compound inwhich the correct metal in the correct oxidation state (see above) ispresent and bonded to a triflate or similar anion will be a catalyst.Such a compound must of course be reasonably stable during thepolymerization (or depolymerization, see below), or decompose to anothercompound which is still a triflate (or similar anion) compound of themetal in the correct oxidation state. It has been found that, ingeneral, the greater the number of triflate groups bonded to the metalcation, the more active the metal compound will be as a catalyst. It ispreferred if half or more of the anions (Z) bound to each metal cationis triflate or a similar anion.

The metal catalysts of the first polymerization may optionally containone or more neutral ligands coordinated to the metal. By a neutralligand is meant a neutral compound that can coordinate with thecatalysts, usually the metal cation. Neutral ligands include water, andethers such as dimethyl ether and tetrahydrofuran.

The metals catalysts of the first polymerization may contain otheranions than triflate and similar anions, and tetrafluoroborate, althoughat least one of triflate or tetrafluoroborate anions must be present.Some other useful anions are alkoxide, particularly lower alkoxidecontaining 1-4 carbon atoms, acetylacetonate, cyclopentadieneide,pentamethylcyclopentadieneide, t-butylacetylacetonate, and halide. It ispreferred if all of the anions are triflate.

In general, in the first polymerization the higher the molar ratio ofmetal compound to cyclic ether monomer originally present, the lower themolecular weight of the resulting polyether will be. Similarly, thehigher the ratio of accelerator (if present) to monomer originallypresent, the lower the molecular weight of the polyether will be. It isbelieved the effects of these two ratios are cumulative. For theseeffects see Examples 7 and 8.

The first polymerization may be run at a temperature of about -80° C. toabout 130° C. If this temperature is above the boiling point of thecyclic ether monomer, a pressure vessel may be used. A preferredtemperature is ambient to the boiling point of the monomer, or 110° C.,whichever is lower. An inert solvent such as di-n-butyl ether, diethylether or toluene may be used, but it is preferred if solvents are notpresent. Protic compounds such as water, methanol and ethanol shouldpreferably not be present, and it is convenient to exclude them bydrying the starting materials and keeping the process under an inert drygas such as nitrogen. As in most chemical processes, the ingredientsshould be mixed at least initially. Continued agitation is preferred toassure that the process materials remain well mixed, and to avoidoverheating. The polymerization is mildly exothermic. If thepolymerization temperature goes up appreciably, refluxing of the monomermay be used to help cool the process.

The polymers produced in the first polymerization often havepolydispersities significantly less than 2, which is possibly indicativeof a "Living polymerization". Also indicative of this is the fact thatas the polymerization proceeds, the molecular weight, particularly thenumber average molecular weight, increases.

In the second and third polymerizations, the terms oxirane, oxetane,oxepane, 1,3-dioxolane, 1,3,5-trioxane, and tetrahydrofuran includecompounds containing those ring systems which are substituted withhydrocarbyl or hydrocarbylene groups containing 1 to 20 carbon atoms.The hydrocarbylene groups form carbocyclic rings, which includebicyclic, tricyclic, etc. systems. By a hydrocarbylene group herein ismeant a divalent radical containing carbon and hydrogen which is part ofa carbocyclic ring.

In the second and third polymerizations preferred cyclic ethers have theformula ##STR2## wherein n is 2 or 4, and each R¹, R², R³ and R⁴ isindependently hydrogen or hydrocarbyl containing 1 to 20 carbon atoms.Some cyclic ethers polymerize to give repeat units of the formula --CHR¹ (CR² R³)_(n) CHR⁴ O!--. In a more preferred cyclic ether all of R¹,R², R³ and R⁴ are hydrogen. In another more preferred cyclic ether wheren=2, R¹, one of R², both of R³ and R⁴ are hydrogen, and the remaining R²is alkyl containing 1-4 carbon atoms, especially preferably theremaining R² is methyl. By hydrocarbyl herein is meant a univalentradical containing carbon and hydrogen.

The second and third polymerizations are carried out in the presence ofan accelerator (sometimes also called a co-catalyst). Suitableaccelerators are carboxylic anhydrides, acyl halides and carboxylicacids whose pKa is less than about 6 in water.

By a carboxylic anhydride is meant a compound containing the grouping--C(O)O(O)C--, wherein the free valencies are to other carbon atoms. Apreferred carboxylic anhydride is an anhydride of an alkyl carboxylicacid or a halogen substituted alkyl carboxylic acid, and particularlypreferred anhydrides are acetic anhydride and trifluoroacetic anhydride.

By a carboxylic anhydride is meant a compound containing the grouping--C(O)X, where X is chlorine or bromine and the free valence it toanother carbon atom. In preferred acyl halides X is chlorine. Preferredacyl halides are alkyl acyl halides, and especially preferred are acetylhalides, more preferably acetyl chloride.

In the second and third polymerizations, by a carboxylic acid is meant acompound containing the grouping --C(O)OH, wherein the free valence isto another carbon atom. Preferred carboxylic acids have a pKa of lessthan 5 in water. Useful carboxylic acids include, but are not limited toformic, acetic, trifluoroacetic, chloroacetic, benzoic, trichloroacetic,p-nitrobenzoic, butyric, and naphthoic acids. Preferred carboxylic acidsare trifluoroacetic, formic, acetic, cyanoacetic, nitropropionic,nitrobenzoic, acrylic and methacrylic. These and other acids thatthemselves don't cause polymerization of the cyclic ethers are alsobelieved to be accelerators, especially if their pKa in water is about 6or less.

When carboxylic anhydride is present one half or more of the end groupsare carboxylic esters. As is known to the artisan, these may behydrolyzed to hydroxyl groups by reaction with water, preferably in thepresence of a catalyst, such as a strong acid (sulfuric acid forinstance) or a strong base (such as NaOH). The proportion of acetateends increases the longer the polymerizationis allowed to proceed.Although the polymeric diol is often the desired product (it can be usedto make other polymers, such as polyurethanes and polyesters), the halfester or diester is also useful, as in relatively low molecular weightpolymers which can be used as solvents.

When acyl halides are used as the accelerator, the end groups areusually ester on one end, and the halide, X, on the other. Thus thecomplete formula for such a polymer could be X-- CHR¹ (CR² R³)_(n) CHR⁴O!--C(O)Y, where Y is the group to which the acyl group of the acylhalide was bound. Such polymers are useful as intermediates for thepreparation of polymers containing different functional groups. Forexample, the ester may be hydrolyzed to a hydroxyl group, and the halidemay be reacted to form another functional group such as nitrile. If abis(acyl halide), X(O)CYC(O)X, is used as the accelerator, the productof the polymerization will be a polyether with halide (X) end groupswhich contains two internal ester groups, and may have the formula X--CHR¹ (CR² R³)_(n) CHR⁴ O!--C(O)YC(O)-- OCHR¹ (CR² R³)_(n) CHR⁴ !--X.Useful bis(acyl halides) include adipoyl chloride, terephthaloylchloride, and diglycolyl chloride Cl(O)CCH₂ OCH₂ C(O)Cl!.

In the second and third polymerizations, when a carboxylic acid is usedas the accelerator, the end groups are usually mostly ester. Thus thecomplete formula for such a polymer could be Y--C(O)--O-- CHR¹ (CR²R³)_(n) CHR⁴ O!--C(O)Y, where Y is the group to which the acyl group ofthe carboxylic acid was bound. The ester group may be hydrolyzed asdescribed above in the paragraph describing the products when acarboxylic anhydride is used as the accelerator.

The second and third polymerizations may be run at a temperature ofabout -80° C. to about 130° C. If this Useful bis(acyl halides) includeadipoyl chloride, temperature is above the boiling-point of the cyclicether monomer, a pressure vessel may be used. A preferred temperature isambient to the boiling point of the monomer or 110° C., whichever islower. An inert solvent such as di-n-butyl ether, diethyl ether ortoluene may be used, but it is preferred if solvents are not present.Protic compounds such as water, methanol and ethanol should preferablynot be present, and it is convenient to exclude them by drying thestarting materials and keeping the process under an inert dry gas suchas nitrogen or dry air. As in most chemical processes, the ingredientsshould be mixed. Continued agitation is preferred to assure contact ofthe process liquids with the heterogeneous catalyst, and to avoidoverheating. The polymerization is mildly exothermic. If thepolymerization temperature goes up appreciably, refluxing of the monomermay be used to help cool the process.

The second and third polymerizations may be run in a variety of methods,such as batch, semi-continuous, or continuous. While the heterogeneouscatalyst may be recovered each time, as by filtration, and reused, inanother embodiment the catalyst is fixed in place and the polymerizationmass circulated or agitated so that uniform contact with the catalystsurface is obtained. In this way, the catalyst may be used for longperiods in a continuous process, or for many batches in a batchpolymerization, without the need to recover the catalyst. Contact timeof the liquid reaction mass with the catalyst will depend on manyfactors, such as the catalytic metal used, its concentration on thecatalyst, the temperature, cyclic ether being polymerized, etc., butwill usually be in the range of a few minutes to a few hours.

Catalysts used herein in the second and third polymerizations containselected metal cations. Preferred metal cations are those of strontium,scandium, yttrium, the rare earth metals, titanium, zirconium, hafnium,vanadium, niobium, tantalum, chromium, molybdenum, tungsten, rhenium,iron, ruthenium, palladium, copper, gold, zinc, tin and bismuth. Morepreferred metals are yttrium, the rare earth metals, scandium andzirconium. Especially preferred metals are yttrium, ytterbium,dysprosium, erbium, neodymium, lanthanum, scandium and zirconium.Another preferred metal is "mischmetall" (sometimes also called"didymium"), which is a mixture of rare earth metals as obtained fromthe ore. By rare earths herein is meant lanthanum, cerium,praeseodymium, neodymium, promethium, samarium, europium, gadolinium,terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.By a perfluoroalkylsulfonate herein is meant a metal salt of aperfluoroalkylsulfonate in which the metal is bonded to one or moreperfluoroalkylsulfonate groups.

The catalyst used in the second polymerization herein is a zeolite inwhich some of the metal cations present are the cations listed above.The anions of such cations are not critical, and may be those normallyfound in zeolites. The zeolites containing the appropriate metal cationscan be made by the ion exchange of cations in known zeolites. Such ionexchange processes are know to the artisan, see for instance D. W. Breckin Zeolite Molecular Sieves, R. E. Krieger Publishing Co., Malabar,Fla., 1984 and Examples 7, 9, 12, 14, 16, 18, and 20. It is preferred ifat least 0.5 atom percent of the metals and metalloids in the zeoliteare one of the useful "catalytic" metals, more preferably at least 5atom percent. It has been found that the zeolite catalysts usually yieldpolyethers with bimodal molecular weight distributions.

The catalyst of the third polymerization, a "catalytic" metalperfluoroalkylsulfonate is attached to the surface of a material that ineffect acts as a heterogeneous support for the metalperfluoroalkylsulfonate. The metal is not attached to the surfacethrough the perfluoroalkylsulfonate, but through another bond or ligand.The catalytic metal should have at least one perfluoroalkylsulfonateanion attached to it, and preferably, except for the group attaching themetal to the support surface, all of the groups should beperfluoroalkylsulfonate.

In the third polymerization catalyst, the metal may be attached to thesurface by a covalent bond, or coordination, or any other method. It ispreferred if significant amounts. (>25%, preferably <10%) of thecatalytic metal cannot be leached from the heterogeneous catalyst by thepolymerization process liquids. In one method of attachment, a ligandwhich can coordinate with the metal cation is attached via one or morecovalent bonds to the surface of the support, and then the metal cationis coordinated to the ligand, thereby fixing the metal cation on thesupport surface. Particularly useful for such are silicon compounds towhich the ligand is attached by a stable (to hydrolysis and thepolymerization process conditions) bond, and in which the silicon isdirectly attached to groups which are readily hydrolyzed. When thesehydrolytically unstable groups are hydrolyzed from the silicon atom, theresulting "compound" can readily bond to surfaces which have hydroxylgroups present. Many common supports, such as alumina, silica (gel),many metal oxides, and the metal cation is attached via one or morecovalent to the surface, an appropriate metal compound is contacted withthe surface containing the ligands, and the metal cation becomes fixedto the support surface. See Examples 177, 179, 181, and 183 for suchprocesses.

The heterogeneous supports for such third polymerization catalysts canbe those which are commonly used for supported catalysts. It ispreferred if they have a relatively large surface area, at least 25 m²/gm, and it is also preferred if the support is inorganic (inorganicincludes various forms of carbon, such as activated carbon, graphite,etc.). Useful supports include alumina, silica, silica-aluminates,carbon, zirconia, yttria, magnesia, ceria, aluminum fluoride and bariumsulfate. Preferred supports are alumina, silica, silica-aluminates,carbon and zirconia. It is preferred if the supports themselves areacidic. Although not critical, a convenient amount of the catalyticmetal on the catalyst is about 0.1 to about 20 weight percent, measuredas catalytic metal.

In the fourth polymerization process a tetrahydrofuran is copolymerizedwith a polycarboxylic acid to yield a poly(ether-ester). By atetrahydrofuran (THF) is meant the common meaning, a compound containinga saturated five membered ring in which one of the ring atoms is oxygenand the other four ring atoms are carbon. Preferred tetrahydrofuranshave the formula I ##STR3## wherein each R¹, R², R³ and R⁴ isindependently hydrogen or hydrocarbyl containing 1 to 20 carbon atoms.In especially preferred THFs, R¹, one of R² and all of R³ and R⁴ arehydrogen, and the remaining R² is alkyl containing 1-4 carbon atoms,particularly the remaining R² is methyl. In another especially preferredembodiment all of R¹, R², R³ and R⁴ are hydrogen.

In the fourth polymerization a tetrahydrofuran is copolymerized with apolycarboxylic acid of the formula A(CO₂ H)_(x), wherein A is an organicradical, and wherein A is bound to each carboxyl group through a carbonatom. By "through a carbon atom" is meant that each carboxyl group isbound to a carbon atom which is part of A. A may contain any substituentwhich does not react during, or disturb, the fourth polymerization.Suitable functional groups include halo, ester, amide, urethane, urea,keto, ether, imide, and sulfone, and hydrocarbon based "functionalgroups" such as olefins, aromatic rings, and acetylenic bonds.Especially preferred functional groups are ester, amide, imide, urethaneand urea. The functional groups should be picked so that they don'tundergo an acid base reaction with the carboxyl groups of thepolycarboxylic acid. Thus aliphatic amine groups should not be presentand are classified as among those groups which interfere with thepolymerization.

Useful polycarboxylic acids include, but are not limited to, maleicacid, fumaric acid, succinic acid, adipic acid, isophthalic acid,terephthalic acid, and 1,2,4-benzenetricarboxylic acid. Preferredpolycarboxylic acids are adipic, isophthalic and terephthalic acids.

The polycarboxylic acid has a pKa of less than 6, preferably less than5, and should not by itself catalyze the polymerization of thetetrahydrofuran. In preferred polycarboxylic acids, x is 2 (adicarboxylic acid). When x is more than two, a branched and/or aliphaticamine groups should not be present and are

The catalyst for the fourth polymerization may be a yttrium or rareearth compound of the formula MZ₃ where M is a trivalent ion of yttrium,or one of the rare earths, lanthanum, cerium, praeseodymium, neodymium,promethium, samarium, europium, gadolinium, terbium, dysprosium,holmium, erbium, thulium, ytterbium, and lutetium.

Preferred metals in the fourth polymerization, M, are strontium,scandium yttrium, the rare earth metals, titanium, zirconium, hafnium,vanadium, niobium, tantalum, chromium, molybdenum, tungsten, rhenium,iron, ruthenium, palladium, copper, gold, zinc, tin and bismuth. Morepreferred metals are yttrium, the rare earth metals, and scandium.Especially preferred metals are yttrium, ytterbium, dysprosium, erbium,neodymium, lanthanum, and scandium. Another preferred metal is"mischmetall" (sometimes also called "didymium"), which is a mixture ofrare earth metals as obtained from the ore.

It is believed monovalent anions that are relatively nonnucleophilic areuseful as Z. Examples of such anions are tetraphenylborate, R⁵ SO₃ ,wherein R⁵ is perfluoroalkyl, or wherein R⁵ is part of a fluorinatedpolymer wherein the carbon atoms alpha and beta to a sulfonate group aretogether bonded to at least 4 fluorine atoms (as in --CF₂ CF₂ SO₃ ). Itis preferred if R⁵ is perfluoroalkyl. In a particularly preferred R⁵ istrifluoromethyl, and that anion is herein called "triflate".

Generally speaking, any metallic compound in which the correct metal inthe correct oxidation state (see above) is present and bonded to atriflate or a similar anion will be a catalyst in the fourthpolymerization. Such a compound must of course be reasonably stablerelatively nonnucleophilic are useful as Z. Examples of compound whichis still a triflate (or similar anion) compound of the metal in thecorrect oxidation state.

The metal catalysts in the fourth polymerization may optionally containone or more neutral ligands, Q, coordinated to the metal. By a neutralligand is meant a neutral compound that can coordinate with thecatalysts, usually the metal cation. Neutral ligands include water, andethers such as dimethyl ether and tetrahydrofuran. Useful compoundscontaining neutral ligands includebis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonate)zirconiumandbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonate)hafnium.

In general, in the fourth polymerization the higher the molar ratio ofmetal compound to cyclic ether monomer originally present, the lower themolecular weight of the resulting polyether will be.

The fourth polymerization may be run at a temperature of about -80° C.to about 130° C. If this temperature is above the boiling point of thecyclic ether monomer, a pressure vessel may be used. A preferredtemperature is ambient to the boiling point of the monomer, or 110° C.,whichever is lower. An inert solvent such as di-n-butyl ether, diethylether or toluene may be used, but it is preferred if solvents are notpresent. Protic compounds such as water, methanol and ethanol shouldpreferably not be present, and it is convenient to exclude them bydrying the starting materials and keeping the process under an inert drygas such as nitrogen. As in most chemical processes, the ingredientsshould be mixed at least initially. Continued agitation is preferred toassure that the process materials remain well mixed, and to avoidoverheating. The polymerization is mildly exothermic. If thepolymerization temperature goes up appreciably, refluxing of the monomermay be used to help cool the process.

The molar ratio of THF to polycarboxylic acid at the beginning of thefourth polymerization can be about 0.2 to about 60, preferably about 2to about 15. Generally speaking, the higher the relative molar amount ofpolycarboxylic acid present, the greater the incorporation (per THFunit) of ester units (from polycarboxylic acid) will be. The desiredamount of ester present will depend on the polycarboxylic acid used, andthe use of the polymeric product.

However, in the fourth polymerization the ratio of equivalents ofcarboxylic acid groups (in the polycarboxylic acid) to the number ofmoles of catalyst (MZ₃.Q_(t)) should be less than six (i.e., carboxylpresent/moles catalyst <6). In a simple batch reaction this means thisratio will be less than 6 at the start of the polymerization, anddecrease as the polycarboxylic acid is polymerized, and its carboxylgroups are "used up" and converted to ester groups. However, as thecarboxyl groups are used up by polymerization, they may be replaced bythe addition of polycarboxylic acid, so long as the above ratio is lessthan 6.

In the fourth polymerization when a dicarboxylic acid (x=2) is used inthe polymerization, a (product) polymer repeat unit can be representedby the general formula

     (--CHR.sup.1 CR.sup.2 R.sup.3 CR.sup.2 R.sup.3 CHR.sup.4 O--).sub.n C(O)AC(O)O--!

wherein all of the symbols have the definitions as given above, and n isan integer of 1 or more. In preferred polymers, n is about 5 to about500, more preferably about 8 to about 100. Useful A groups includetetramethylene, p-phenylene, and m-phenylene.

In another preferred polymer product of the fourth polymerization, n is5 or more, more preferably 10 or more. It is preferred if A containsurea or urethane groups. By a urea group is meant --NH--C(O)--NR¹⁰ --,and by a urethane group is meant --O--C(O)--NH--, wherein R¹⁰ ishydrogen or hydrocarbyl containing 1 to 20 carbon atoms. It is preferredif R¹⁰ is hydrogen. In other preferred polymers, all of R¹, R², R³ andR⁴ are hydrogen, or one of R² is methyl, the other R² is hydrogen, andall of R¹, R³, and R⁴ are hydrogen.

A preferred polymer product of the fourth polymerization is one in whichA has the formula

    --R.sup.6 --E--C(O)--NH--R.sup.7 --NH--C(O)--E-- --R.sup.8 --E--C(O)--NH--R.sup.7 --NH--C(O)--E--!.sub.m --R.sup.6 --

wherein each R⁶, R⁷ and R⁸ is independently hydrocarbylene orsubstituted hydrocarbylene containing 2 to 25 carbon atoms, E is --O--or --NR¹⁰ --, wherein R¹⁰ is as defined above, and m is an average of 0to 10. Such polymers are made from dicarboxylic acids A(CO₂ H)_(x),wherein x is 2, and A has the formula shown above. Such diacids can bemade by the reaction of one or more diisocyanates with one or moreaminocarboxylic acids, hydroxy carboxylic acids, diamines, aminoalcoholsand diols. The group R⁶ is derived from the amino- or hydroxycarboxylicacid, R⁷ is derived from an organic diisocyanate, and R⁸ is derived froma diamine or diol. When a particular E is --O--, it can be derived fromthe reaction of an isocyanate group and a hydroxy group to form aurethane. When a particular E is --NR¹⁰ --, it can be derived from thereaction of an isocyanate and a primary amino group when R¹⁰ ishydrogen, and a secondary amino group when R¹⁰ is hydrocarbyl, to form aurea. All preferred formulas for dicarboxylic acids also refer to "A" inthe polymer.

Dicarboxylic acids containing various functional groups can be made bymethods known in this art. See, for instance, Chem. Abs., Vol. 44, 5104b-d (1950), S. Hsiao, et al., J. Polym. Sci., Part A, Vol. 28, pp.2169-2178 (1990), and R. E. Asay et al., J. Heterocyclic Chem., Vol. 14,pp. 85-90 (1977).

To give a concrete example, if it is desired to make the dicarboxylicacid wherein both of R⁶ are 1,4-phenylene, R⁷ is ##STR4## R⁸ is1,4-phenylene, every E is --NH--, and m is an average of 1, one couldreact (preferably in solution) one mole of p-phenylene diamine, twomoles of p-aminobenzoic acid, and two moles ofbis(4-isocyanatophenyl)methane. To prepare the corresponding polymerwhere every E is --O--, one would use hydroquinone and p-hydroxybenzoicacid in place of p-phenylenediamine and p-aminobenzoic acid,respectively. To vary m, the ratio of diamine, diol and/or aminomonoolto aminocarboxylic acid and/or hydroxyacid would be varied. The amountof diisocyanate would also be changed so it could react with all of theamino and/or hydroxy groups present. As the art skilled will understand,in reactions of this type, a distribution of m values will be obtained(except when m is 0) for individual molecules, and overall, m is thearithmetic average of the values for individual molecules. Fractionalvalues of m are possible by varying the stoichiometry. Experiment 1illustrates the preparation of such a dicarboxylic acid.

In preferred dicarboxylic acids:

R⁶ and R⁸ are each independently 1,4-phenylene, 1,3-phenylene, andn-alkylene containing 2 to 6 carbon atoms;

R⁷ is 1,4-phenylene, 1,3-phenylene, n-alkylene containing 2 to 6 carbonatoms, or ##STR5##

In especially preferred dicarboxylic acids:

R⁶ and R⁸ are each independently 1,4-phenylene, 1,3-phenylene, andn-alkylene containing 2 to 6 carbon atoms;

R⁷ is ethylene, or ##STR6##

In other preferred dicarboxylic acids E is --NR¹⁰ -- wherein R¹⁰ ishydrogen, or m is an average of 0 to about 3.

By hydrocarbylene in the fourth polymerization and its products is meanta divalent radical containing only carbon and hydrogen. A substitutedhydrocarbylene is a radical which also contains substituent groups thatdo not interfere with any of the reactions, including polymerization,described herein. Suitable functional groups have been listed above.

The polymeric product of the fourth polymerization, particularly onemade from dicarboxylic acids containing other functional groups, isuseful as a thermoplastic elastomer, urethane rubber or in spandexfiber. The ester groups of the poly(ester-ether) may be hydrolyzed toform polyether diols.

This invention is also concerned with the first depolymerization of apolymer consisting essentially of the repeat unit -- CHR¹ CR² R³ CR² R³CHR⁴ O!-- wherein R¹, R², R³, and R⁴ are defined above, and preferredcombinations are as given above for the first polymerization processwhen n=2. A catalyst designated MZ₃.Q_(t) is used, wherein M, S, Q, t,and Z, and their preferred embodiments, are as given above for the firstpolymerization.

The first depolymerization process is carried out at about 100° C. toabout 250° C., preferably about 130° to about 200° C. Although air canbe used to blanket the process, it is preferred to use an inertatmosphere such as nitrogen to avoid possible side reactions. Thepolytetrahydrofuran need not be dried before use. A solvent may be used,but it is preferred to carry out the process without solvent.

The amount of catalyst compared to polyether present in the firstdepolymerization is not critical, 0.1-15% by weight being useful,preferably about 1 to 3% by weight of catalyst.

The first depolymerization process may be carried out by just heatingthe polyether in the presence of the catalyst. In order to avoid boilingoff the often volatile tetrahydrofurans, a pressure vessel may beneeded. However, it is preferred to carry out the depolymerization whileconstantly distilling off the (substituted) tetrahydrofuran as it forms.It is believed that this ensures driving this process to produce themonomeric tetrahydrofuran. The recovered monomeric tetrahydrofuran maybe used in the polymerization to form a polytetrahydrofuran.

Both the first polymerization and first depolymerization processes canbe done in a variety of ways known to the artisan. The firstpolymerization can be done by batch, semi-batcj and continuousprocesses. Continuous processes include continuous stirred tankreactor(s) with one or more stages, and/or plug flow reactors (seeExample 19). The first depolymerization process can also be done bysimilar methods. In this process, a continuous process could be constantaddition of polyether to the reactor, while distilling off a similaramount of a monomeric tetrahydrofuran. Other variations will be evidentto one skilled in this art.

In both the first polymerization and first depolymerization processesdisclosed herein the catalyst may be recovered and reused in eitherprocess. It may be recovered from the polymerization process byextracting the polymer formed with water, while it can be recovered fromthe depolymerization process by extracting the distillation residue withwater. In both instances, the recovered catalyst may be used again in apolymerization or depolymerization process. In both instances theaqueous washings may be concentrated by removal of the water (as byevaporation) and the solid catalyst recovered. See Examples 20, and28-32 for recovery and reuse of catalyst.

The second depolymerization process is carried out at about 100° C. toabout 250° C., preferably about 130° C. to about 200° C. Although aircan be used to blanket the process, it is preferred to use an inertatmosphere such as nitrogen to avoid possible side reactions. A solventmay be used, but it is preferred to carry out the process withoutsolvent.

The amount of catalyst compared to polyether present is not critical,0.1-15% by weight (percent of the catalyst to polyether) being useful,preferably about 1 to 3% by weight of catalyst.

The second depolymerization process may be carried out by just heatingthe polyether in the presence of the heterogeneous catalyst. In order toavoid boiling off the often volatile tetrahydrofurans, a pressure vesselmay be needed. However, it is preferred to carry out thedepolymerization while constantly distilling off the (substituted)tetrahydrofuran as it forms. It is believed that this ensures drivingthis process to produce the monomeric tetrahydrofuran.

In both the second and third polymerization and second depolymerizationprocesses disclosed herein heterogeneous catalysts may be recovered andreused in any of the processes. It may be recovered from the processesby filtration, and if desired, drying. The recovered catalyst may beused again in the polymerization or depolymerization processes.

All of the above processes may be carried out as batch, semibatch orcontinuous processes. For all of the processes, continuous typeprocesses are preferred.

In the Examples, the following abbreviations are used:

ACA--acetic anhydride

DETM--diethyl 2- 3-(triethoxysilyl)propyl)!malonate

DMAC--N,N-dimethylacetamide

GPC--gel permeation chromatography

MDI--bis(4-isocyanatophenyl)methane

Nafion™--a sulfonated perfluoropolymer produced by E. I. du Pont deNemours and Company, Wilmington, Del., USA

Mn--number average molecular weight

Mw--weight average molecular weight

RB--round bottom

PD--polydispersity (Mw/Mn)

PS--polystyrene

SS--stainless steel

STD--standard

THF--tetrahydrofuran

EXAMPLE 1 Polymerization of THF with Yttrium Triflate and AceticAnhydride

In a dry box, yttrium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box andnitrogen bleeds attached. THF (20 mL) followed by acetic anhydride (0.75mL) were added to each flask. After 15, 30 and 45 minutes, apolymerization was terminated via the addition of 5% NaOH (10 mL) andTHF (50 mL). The resulting organic phases were separated andconcentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  56.76    8180        17100 2.09                                     30 mins.  67.02    6630        14600 2.20                                     45 mins.  73.11    6210        13300 2.02                                     ______________________________________                                    

EXAMPLE 2 Polymerization of THF with Ytterbium Triflate and AceticAnhydride

In a dry box, ytterbium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) followed by aceticanhydride (0.75 mL) were added to each flask. After 15, 30, 45 and 60minutes, a polymerization was terminated via the addition of 5% NaOH (10mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  56.09    8400        16200 1.93                                     30 mins.  67.98    7360        14900 2.03                                     45 mins.  69.67    5890        13100 2.22                                     60 mins.  71.31    6010        12800 2.15                                     ______________________________________                                    

EXAMPLE 3 Polymerization of THF with Dysprosium Triflate and AceticAnhydride

In a dry box, dysprosium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20 mL) followed by aceticanhydride (0.75 mL) were added to each flask. After 15, 30, 45 and 60minutes, a polymerization was terminated via the addition of 5% NaOH (10mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  52.03    7260        15700 2.17                                     30 mins.  63.86    7220        15700 2.18                                     45 mins.  70.05    6250        14300 2.30                                     60 mins.  71.36    6010        13700 2.29                                     ______________________________________                                    

EXAMPLE 4 Polymerization of THF with Erbium Triflate and AceticAnhydride

In a dry box, erbium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Aftersealing with rubber septa the flasks were removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) followed by aceticanhydride (0.75 mL) were added to each flask. After 15, 30, 45 and 60minutes, a polymerization was terminated via the addition of 5% NaOH (10mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  52.82    8460        15900 1.89                                     30 mins.  62.96    7390        17100 2.32                                     45 mins.  66.79    8070        16400 2.04                                     60 mins.  68.20    7250        16100 2.22                                     ______________________________________                                    

EXAMPLE 5 Polymerization of THF with Lanthanum Triflate and AceticAnhydride

In a dry box, lanthanum triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetic anhydride (0.75mL) were added to each flask. After 15, 30, 45 and 60 minutes, apolymerization was terminated via the addition of 5% NaOH (10 mL) andTHF (50 mL). The resulting organic phases were separated, concentratedat reduced pressure and then dried under vacuum. Polymer yields and GPCanalysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  5.60     9780        13990 1.42                                     30 mins.  11.27    13700       20900 1.53                                     45 mins.  40.30    17000       28100 1.65                                     60 mins.  59.24    15800       33400 2.11                                     ______________________________________                                    

EXAMPLE 6 Polymerization of THF with Neodymiuum Triflate and AceticAnhydride

In a dry box, to an oven dried 100 mL RB flask equipped with a stirringbar was added neodymium triflate (0.75 g). The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (20 mL) followed by acetic anhydride (0.75 mL) wereadded. After 30 minutes the polymerization was terminated via theaddition of 5% NaOH (10 mL) and THF (50 mL). The resulting organic phasewas separated, concentrated at reduced pressure and then dried undervacuum yielding 7.56 g (42.6%) of polymer. GPC analysis: Mn=8460,Mw=22300, PD=2.65 (PS STD).

EXAMPLE 7 Polymerization of THF with Yttrium Triflate and AceticAnhydride

In a dry box, yttrium triflate (0.75 g) was added to each of three ovendried 100 mL RB flasks equipped with stirring bars. The flasks weresealed with rubber septa and removed from the dry box. Nitrogen bleedswere attached and THF (20 mL) added to each flasks. Acetic anhydride(0.25, 0.50 and 0.75 mL) was added respectively to each flask. After 60minutes the polymerizations were quenched via the addition of 5% NaOH(10 mL) and THF (50 mL), the resulting organic phases were separated,concentrated at reduced pressure and then dried in vacuo overnight.Polymer yields and GPC analysis:

    ______________________________________                                        Acetic    Polymer  Mn                                                         Anhydride Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        0.25 mL   75.02    8080        18100 2.25                                     0.50 mL   73.33    6940        14900 2.15                                     0.75 mL   75.20    5080        13600 2.68                                     ______________________________________                                    

EXAMPLE 8 Polymerization of THF with Yttrium Triflate and Aceticanhydride

In a dry box, to three 100 mL RB flasks equipped with stirring bar wereadded 0.25, 0.50 and 1.00 g yttrium triflate respectively. The flaskwere sealed with rubber septa and removed from the dry box. Nitrogenbleeds were attached and THF (20 mL) and acetic anhydride (1.00 mL) wereadded to each flask. After 60 minutes the polymerizations wereterminated via the addition of 5% NaOR (10 mL) and THF (50 mL). Theresulting organic phases were separated, concentrated at reducedpressure and dried under vacuum overnight. Polymer yields and GPCanalysis:

    ______________________________________                                        Yttrium  Polymer  Mn                                                          Triflate Yield (%)                                                                              (PS STD)    Mw    PD                                        ______________________________________                                        0.25 g   50.11    11300       26200 2.02                                      0.50 g   70.79    8060        17600 2.16                                      1.00 g   81.96    4820        10500 2.09                                      ______________________________________                                    

EXAMPLE 9 Polymerization of THF with Yttrium Triflate and AceticAnhydride in Diethyl Ether

In a dry box, yttrium triflate (0.75 g) was weighed into an oven dried100 mL RB flask equipped with addition of 5% NaOR (10 mL) and THF (50mL). The apparatus sealed with a rubber septum and removed from the drybox. A nitrogen bleed was attached and diethyl ether (20 mL), THF (20mL) and acetic anhydride (0.75 mL) were added. After 60 minutes thepolymerization was quenched via the addition of 5% NaOH (10 mL) anddiethyl ether (50 mL). The resulting organic phase was separated,concentrated and dried under vacuum. Yield: 3.86 g (21.76%). GPCanalysis: Mn=2960, Mw=7800, PD=2.63 (PS STD).

EXAMPLE 10 Polymerization of THF with Yttrium Triflate and AceticAnhydride in Toluene

In a dry box, yttrium triflate (0.75 g) was weighed into an oven dried100 mL RB flask equipped with a stirring bar. After sealing with arubber septum, removal from the dry box, and attachment of a nitrogenbleed, toluene (20 ml), THF (20 mL) and acetic anhydride (0.75 mL) wereadded. After 60 minutes the polymerization was terminated via theaddition of 5% NaOH (10 ml) and toluene (50 mL). The resulting organicphase was separated, concentrated at reduced pressure and then driedunder vacuum. Yield: 1.73 g (9.75%). GPC analysis: Mn=1150, Mw=2700,PD=2.34 (PS STD).

EXAMPLE 11 Copolymerization of THF/3-Methyl-THF with Yttrium Triflateand Acetic Anhydride

In a dry box, yttrium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry boxwherein nitrogen bleeds were attached. THF (15 mL) and 3-methyl-THF (5mL) followed by acetic anhydride (0.75 ml) were added to each flask.After 15, 30 and 45 minutes, a polymerization was terminated via theaddition of 5% NaOH (10 mL) and THF (50 mL). The resulting organicphases were separated, concentrated at reduced pressure and then driedunder vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  39.50    6920        12400 1.80                                     30 mins.  51.63    6280        13200 2.11                                     45 mins.  57.27    5860        12700 2.17                                     ______________________________________                                    

¹ H NMR analysis showed ˜12-13% incorporation of 3-methyl-THF in thepolymers.

EXAMPLE 12 Polymerization of THF with Yttrium Triflate andTrifluoroacetic Anhydride

In a dry box, yttrium triflate (0.75 g) was weighed in an oven dried 100mL RB flask equipped with a stirring bar. After sealing with a rubberseptum and removal from the dry box and attachment of a nitrogen bleedTHF (20 mL) was added followed by trifluoroacetic anhydride (3.00 mL).After 2 hrs. the polymerization was quenched by the addition of 5% NaOH(10 mL) and THF (50 mL). Diethyl ether (50 mL) was added to effectseparation of the organic/aqueous phase. The organic phase wasseparated, concentrated at reduced pressure and then dried under vacuum.Yield: 5.40 g (30.44%). GPC analysis: Mn=53900, Mw=86200, PD=1.78 (PSSTD).

EXAMPLE 13 Polymerization of THF with Ytterbium Triflate and PropionicAnhydride

In a dry box, ytterbium triflate (1.00 g) was weighed into an oven dried100 mL RB flask equipped with a stirring bar. The flask was stopperedwith a rubber septum and removed from the dry box and a nitrogen bleedwas attached. THF (20 mL) and propionic anhydride (1.00 mL) were addedvia syringes. After 60 minutes the polymerization was quench with 5%NaOH (10 mL) and THF (50 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried in vacuo. Yield: 12.69 g(71.5%). GPC analysis: Mn 6520, Mw=14500, PD=2.23.

EXAMPLE 14 Polymerization of 3-Methyl-THF with Yttrium Triflate andAcetic Anhydride

In a dry box, yttrium triflate (0.75 g) was weighed into an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and 3-methyl-THF (20 mL) was added followed by acetic anhydride(0.75 g). After stirring overnight the polymerization was terminated bythe addition of 5% NaOH (10 mL) and THF (25 mL). The resulting organicphase was separated, concentrated at reduced pressure and dried undervacuum. Yield: 6.12 g (34.50%). GPC analysis: Mn=437, Mw=808, PD=1.85.

EXAMPLE 15 Polymerization of THF with Yttrium Triflate and AceticAnhydride

In a dry box, yttrium triflate (0.75 g) was weighed into an oven dried100 mL RB flask equipped with a stirring bar. After sealing with arubber septum the flask was removed from the dry box and a nitrogenbleed attached. THF (20 mL) and acetic anhydride (1.00 mL) were added.After 17.5 hrs. THF (20 mL) and acetic anhydride (1.00 mL) were added tothe thick viscous solution. After an additional 2 hrs THF (20 mL) andacetic anhydride were again added to the polymerized solution. Thepolymerization was terminated 2.5 hrs later via the addition of 5% NaOH(20 mL) and THF (100 mL). The organic phase was separated, concentratedat reduced pressure and dried under vacuum. Polymer yield: 32.3 g(61.23%). GPC analysis: Mn=2490, w=8440, PD=3.39 (PS STD).

EXAMPLE 16 Polymerization of THF with Ytterbium Triflate

In a dry box, ytterbium triflate (1.00 g) was weighed in a 100 mL RBflask equipped with a stirring bar. After sealing with a rubber septumthe flask was removed from the dry box and a nitrogen bleed attached.THF (20 mL) was then added via syringe. The polymerization was allowedto proceed overnight and then terminated via the addition of H₂ O (25mL) and diethyl ether (75 mL). The organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 0.520 g (2.93%). GPC analysis: Mn=416000, Mw=842000, PD=2.02 (PSSTD).

EXAMPLE 17 Polymerization of 7-Oxabicyclo 2.2.1!heptane with YtterbiumTriflate and Acetic Anhydride

In a dry box, ytterbium triflate (0.5 g) was weighed into a 100 mL RBflask equipped with a stirring bar. After sealing with a rubber septum,the flask was remove from the dry box and a nitrogen bleed attached.7-oxabicyclo 2.2.1!heptane (10 mL, distilled from potassium carbonate)was added followed by acetic anhydride (0.5 mL). After 1 hr. thepolymerization was terminated by the addition of 5% NaOH (10 mL), THF(75 mL) and diethyl ether (˜50 mL). The organic phase was separate,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 1.00 g. GPC analysis: Mn=233, Mw=522, PD=2.24 (PS STD).

EXAMPLE 18 Polymerization of Cyclohexene Oxide with Lanthanium Triflate

In a dry box, lanthanum triflate (0.75 g) was weighed in a oven dried100 mL three neck flask equipped with a stirring bar, reflux condenserand addition funnel. Toluene (20 mL) was added via syringe andcyclohexene oxide (20 mL) was slowly added via the addition funnel. Thepolymerization was terminated after 2.75 hrs. via the addition of H₂ O(10 mL) and toluene (100 mL). The organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 12.4 g (63.9%). GPC analysis (bimodal distribution): Mn=4510,Mw=25700, PD=5.70 (PS STD).

EXAMPLE 19 Continuous Polymerization of THF with Ytterbium Triflate andAcetic Anhydride

A solution of THF (˜500 mL) and ytterbium triflate (25 g) was chargedinto a 500 mL capacity ISCO pump, which was connected to a 3 way 3.2 mmSS connector ("T" mixer) via 8 cm of 3.2 mm SS tubing containing a checkvalve. A second ISCO pump (500 mL capacity) was charged with ˜100 mL ofacetic anhydride and this was connected to the "T" mixer by 75 cm of 3.2mm SS tubing also containing a check valve. The feed rate of theTHF/ytterbium triflate solution was 3.3 mL/min and that of the aceticanhydride was 0.25 mL/min. The "T" mixer was connected to a glassstirred holdup tank (approximately 60 mL volume) by 12 cm of 3.2 mm SStubing. This tank was then connected to a second stirred holdup tank(approximately 55 mL volume) via Cajon flex tubing with ultra torrfitting (6.4 mm, 13 cm). This in turn was connected to a third glassreactor, plug flow (approximately 60 mL volume), again via Cajon flextubing with ultra torr fitting (6.4 mm, 13 cm). The polymerized solutionexiting from the third reactor was fed to a stirred beaker containingwater/diethyl ether. Each reactor was equipped with thermal well port.During the polymerization the temperature in the first reactorstabilized to 41°-42° C. and that of the second reactor to 31°-32° C.and that of the third reactor 26°-27° C. After the contents of theTHF/ytterbium triflate pump was discharged, and two fractions of polymerwere collected, the pump was again refilled with a solution of THF (˜500mL) and ytterbium triflate (25 g). Three fractions were collected. Thelast fraction was obtained by purging the system with diethyl ether.

The organic phases were separated, concentrated at reduced pressure andthen dried under vacuum giving the following:

    ______________________________________                                        Fraction             Weight                                                   ______________________________________                                        1                    106.86 g                                                 2                    79.59 g                                                  3                    56.97 g                                                  4                    220.2 g                                                  5                    97.2 g                                                   ______________________________________                                    

The aqueous phases from above were collected, concentrated at reducedpressure and then dried under vacuum at 180° C. giving a cream solid,46.98 g, representing a 93.94% recovery of the total ytterbium triflatecatalyst used.

EXAMPLE 20 Polymerization of THF with Ytterbium Triflate (Recovered fromExample 19) and Acetic Anhydride

In a dry box, ytterbium triflate (1.00 g), recovered catalyst fromExample 19, was weighed out in a 100 mL RB flask equipped with astirring bar. A rubber septum was attached and the flask removed fromthe dry box. A nitrogen bleed was attached and THF (20 mL) addedfollowed by acetic anhydride (1.00 mL). After 1 hr. the polymerizationwas terminated by the addition of water (25 mL), THF (25 mL) and diethylether (50 mL), the resulting organic phase was separated, concentratedat reduced pressure, then dried under vacuum affording 13.42 g (75.65%)of polymer.

EXAMPLE 21 Polymerization of THF with Yttrium Triflate and AceticAnhydride at -78° C.

In a dry box, yttrium triflate (0.75 g) was weighed in an oven dried 100mL RB flask equipped with a stirring bar. After sealing with a rubberseptum, removal from the dry box and the attachment of a nitrogen bleed,THF (20 mL) was added. The resulting mixture was cooled to -78° C.Acetic anhydride (0.75 mL) was then added, the polymerization wasterminated 5 hrs. later by the addition of water (25 mL) and diethylether (50 mL). After warming to room temperature the resulting organicphase was separated, concentrated at reduced pressure, then dried undervacuum affording 0.58 g (3.27%) of polymer.

EXAMPLE 22 Preparation of Didymium (Mischmetall) Triflate

Didymium (mischmetall) oxide (17 g) and water (50 mL) were added to a200 mL RB flask equipped with stirring bar and an addition funnel andreflux condenser. Triflic acid (50 g) was slowly added via the additionfunnel to the resulting stirred slurry. After the addition was completeda homogeneous solution resulted, thus an additional 2.0 g of the oxidewas added and the slurry heated to reflux for 2 hrs. The cooled slurrywas filtered, the filtrate concentrated at reduced pressure and thendried under vacuum at 150°-210° C. affording 58.4 g of a pink solid.

EXAMPLE 23 Polymerization of THF with Didymium (Mischmetall) Triflate:Polymerization Time on Polymer Yield

In a dry box, didymium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box andnitrogen bleeds attached. THF (20 mL) followed by acetic anhydride (0.75mL) were added to each flask. After 15, 30, 45 and 60 minutes, apolymerization was terminated via the addition of 5% NaOH (10 mL) andTHF (50 mL). The resulting organic phases were separated, concentratedat reduced pressure and then dried under vacuum. Polymer yields:

    ______________________________________                                        Polymer Time  Polymer Yield (%)                                               ______________________________________                                        15 mins.      13.92                                                           30 mins.      34.94                                                           45 mins.      43.74                                                           60 mins       49.4                                                            ______________________________________                                    

EXAMPLE 24 Polymerization of Refluxing THF with Yttrium Triflate andAcetic Anhydride

In a dry box, yttrium triflate (0.75 g) was weighed into an oven dried100 mL flask equipped with a stirred bar, a reflux condenser wasattached, the flask sealed with rubber septum and removed from the drybox and a nitrogen bleed attached. THF (20 mL) was added and theresulting mixture heated to reflux via an oil bath (temp. ˜80° C.).Acetic anhydride (0.75 mL) was added to the stirred refluxing mixture.After 30 minutes the polymerization was terminated via the addition of5% NaOH (10 mL) and THF (50 mL). The cooled organic phase was separated,concentrated at reduced pressure, then dried under vacuum giving 6.44 g(36.30%) of polymer.

EXAMPLE 25 Preparation of Ytterbium Nafion® Salt

In a 300 mL RB flask were added ytterbium oxide (0.75 g) and Nafion®perfluorinated ion exchange resin powder (300 mL, 5 wt. % solution in amixture of lower aliphatic alcohols and 10% water). The resultingmixture was heated to 100° C. and stirred overnight. The resultingsolution was filtered and dried under vacuum at 150° C., affording 9.21g of a light brown solid.

EXAMPLE 26 Polymerization of THF with Ytterbium Nafion® Salt and AceticAnhydride

In a dry box, the ytterbium Nafion® salt (1.00 g, from Example 25) wasadded to each of four oven dried 100 mL RB flasks equipped with stirringbars. The flasks were sealed with rubber septa and removed from the drybox and nitrogen bleeds attached. THF (20 mL) followed by aceticanhydride (1.00 mL) were added to each flask. After 2, 3, 4 and 5 hrs. apolymerization was terminated by the addition of water (25 mL) anddiethyl ether (50 mL). The organic phases were separated, concentratedat reduced pressure and then dried under vacuum to give the following:

    ______________________________________                                        Polymer Time  Polymer Yield (%)                                               ______________________________________                                        2 hrs.        5.24                                                            3 hrs.        11.39                                                           4 hrs.        17.08                                                           5 hrs.        22.66                                                           ______________________________________                                    

EXAMPLE 27 Depolymerization of PolyTHF with Yttrium Triflate

Polytetrahydrofuran 1000 (300 g, Aldrich) and yttrium triflate (9 g)were placed in a 500 mL three neck flask equipped with a stirring bar,Vigreaux column (30.5 cm) and a fractional distillation head. A nitrogenpurge was then attached and all other openings glass stoppered. Theresulting mixture was then heated by an oil bath and the water cleardistillate fractions collected as follows:

    ______________________________________                                                Oil Bath      Head Temp                                               Fraction                                                                              Temp (°C.)                                                                           (°C.)                                                                            Weight                                        ______________________________________                                        1       171-175       64.5      67.49                                         2       176           64.5      71.84                                         3       176           64.5      32.84                                         4       178           64.5      58.67                                         5       178           64.5      56.71                                         ______________________________________                                         Total weight of distillate collected: 287.55                                  .sup.1 H NMR analyses of all five fractions confirmed the product to be       THF.                                                                          Yield (Recovery): 95.85%                                                 

EXAMPLE 28 Depolymerization of Poly-THF with Yttrium Triflate: Reuse ofCatalyst

To the residue remaining from Example 27 was added polytetrahydrofuran1000 (300 g, Aldrich). The apparatus was reassembled the resultingmixture heated by an oil bath, and the resulting water clear distillatefractions were collected as follows:

    ______________________________________                                                Oil Bath      Head Temp                                               Fraction                                                                              Temp (°C.)                                                                           (°C.)                                                                            Weight                                        ______________________________________                                        1       170-174       63-64     43.39                                         2       174           64        62.68                                         3       175           65        66.15                                         4       177           65        55.15                                         5       177           65        32.58                                         ______________________________________                                         Total weight of distillate collected: 259.95 g                                Yield (Recovery): 86.65%                                                      Total time elapsed from start of collection to termination of Example: 2      hrs. 50 mins.                                                            

EXAMPLE 29 Polymerization of Recovered THF with Ytterbium Triflate andAcetic Anhydride

In a dry box, ytterbium triflate (1.00 g) was added to an oven dried 100mL flask equipped with a stirring bar. The flask was then sealed with arubber septum and removed from the dry box and a nitrogen purgeattached. Tetrahydofuran (20 mL) from the fourth fraction of Example 27was added followed by 1 mL of acetic anhydride. After 1 hour nopolymerization was apparent, thus an additional 1 mL of acetic anhydrideadded. After 1 hour the polymerization was terminated via the additionof 5% NaOH and THF (50 mL), the organic phase separated, concentrated atreduced pressure and then dried in vacuo overnight affording 10.31 g(58%) of polymer. GPC analysis: Mn=1970, Mw=6650, PD=3.38 (PS STD).

EXAMPLE 30 Polymerization of Recovered Purified THF with YtterbiumTriflate and Acetic Anhydride

Fractions 2-4 of experiment Example 27 were combined and distilled fromsodium/benzophenone. Twenty mL of this dried THF was added to ytterbiumtriflate (1 g), previously weighed out in an oven dried 100 mL flaskequipped with stirring bar and a nitrogen purge. Acetic anhydride (1 mL)was then added, after 1 hour the polymerization was terminated via theaddition of 5% NaOH and THF (50 mL), the organic phase separated andconcentrated at reduced pressure and then in vacuo, affording 13.32 g(78.08%) of polymer. GPC analysis: Mn=4110, Mw=8860, PD=2.15 (PS STD).

EXAMPLE 31 Recovery of Catalyst from Depolymerization

Water (100 mL) was added to the residue from Example 28, the resultingmixture was stirred at room temperature for approximately 1 hour, theaqueous phase separated and concentrated at reduced pressure and driedin vacuo at 180° C. overnight affording a brown solid. This solid wasagain dissolved in water, then filtrated, the filtrated concentrated atreduced pressure. The resulting solid was dried under vacuum at 180° C.overnight affording a cream solid: 6.48 g (72%) of recovered catalyst.

EXAMPLE 32 Activity of Recovered Catalyst in the Polymerization of THF

In a dry box, the recovered catalyst of Example 31 (1 g) was placed inan oven dried 100 mL flask equipped with a stirring bar. The flask wassealed with a rubber septum and removed from the dry box and a nitrogenpurge attached. THF (20 mL) was then added followed by acetic anhydride(1 mL). After 1 hour the polymerization was terminated via the theaddition of 5% NaOH and THF (50 mL), the organic phase separated,concentrated and dried in vacuo overnight affording 13.86 g (78.13%) ofpolymer. GPC Analysis: Mn=4460, Mw=9280, PD=2.08 (PS STD).

EXAMPLE 33 Depolymerization of Poly-THF/3-Methyl-THF Copolymer withYttrium Triflate

Poly-tetrahydrofuran/3-methyl-tetrahydrofuran copolymer (308.6 g)containing 3385 ppm water and yttrium triflate (9 g) were placed in a500 mL three neck flask equipped with a stirring bar, Vigreaux column(30.5 cm), a thermometer and a fractional distillation head. A nitrogenpurge was attached and all other opening glass stoppered. The resultingmixture was heated by an oil bath and the water clear distillatefractions collected as follows:

    ______________________________________                                               Oil Bath   Rxn.       Head     Weight                                  Fraction                                                                             Temp. (°C.)                                                                       Temp. (°C.)                                                                       Temp. (°C.)                                                                     (g)                                     ______________________________________                                        1      180-182    140-145    65-70    64.35                                   2      182-184    140        69-70    71.03                                   3      183-185    140-144    70       69.35                                   4      185        143        70       70.12                                   5      185        --         70       22.35                                   ______________________________________                                         Total Weight Collected: 297.20 g                                              % Yield (Recovery): 96.47                                                     Total depolymerization time: 2 hrs. 25 mins.                             

EXAMPLE 34 Depolymerization of PolyTHF, Diacetate Capped, with YttriumTriflate

Polytetrahydrofuran which was diacetate capped (300 g, Mn 1850) andyttrium triflate (9 g) were placed in a 500 mL three flask equipped witha stirring bar, Vigreaux (30.5 cm), a thermometer and a fractionaldistillation head. A nitrogen purge was attached and all other openingsglass stoppered. The resulting mixture was heated by an oil bath and thewater clear distillate fractions collected as follows:

    ______________________________________                                               Oil Bath   Rxn.       Head     Weight                                  Fraction                                                                             Temp. (°C.)                                                                       Temp. (°C.)                                                                       Temp. (°C.)                                                                     (g)                                     ______________________________________                                        1      158-160    105-129    64       82.78                                   2      160-161    116-129    64-66    62.91                                   3      161        116        64-67    77.71                                   4      161-180    --         67-69    51.50                                   ______________________________________                                         Total weight Collected: 274.90 g                                              % Yield (Recovery): 91.63                                                     Total depolymerization time: 1 hr. 25 mins.                              

EXAMPLE 35 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumand Acetic Anhydride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of four separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedsTHF (10 ML) and acetic anhydride (0.50 mL) were added to each flask.After 15, 30, 45 and 60 minutes, a polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phases were separated, concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  39.34    12700       14100 1.11                                     30 mins.  54.79    15000       19000 1.27                                     45 mins.  63.92    16000       22100 1.38                                     60 mins.  64.26    17200       24500 1.41                                     ______________________________________                                    

EXAMPLE 36 Polymerization of THF withBis(n-cyclopentadienyl)bis(trifluoromethanesulfonato)titanium and AceticAnhydride

In a dry box,bis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)titanium (0.50 g)was added to each of four separate oven dried 100 mL RB flasks equippedwith stirring bars. The flasks were sealed with rubber septa and thenremoved from the dry box. Nitrogen bleeds were attached and THF (10 mL)and acetic anhydride (0.50 mL) were added to each flask. After 15, 30,45, 70 minutes a polymerization was terminated via the addition of water(25 mL), ether (25 mL) and THF (50 mL). The separated organic phaseswere washed repeatedly with water (3×25 mL), then separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  39.35    10700       12000 1.12                                     30 mins.  61.33    13900       17300 1.25                                     45 mins.  67.08    14200       19300 1.35                                     70 mins.  65.50    12400       19300 1.56                                     ______________________________________                                    

EXAMPLE 37 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumand Acetyl Chloride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of three separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleeds,THF (10 mL) and acetyl chloride (0.375 mL) were added to each flask.After 15, 30, and 45 minutes, a polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phases were washed repeatedly with water (3×25 mL), separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  59.86    7980        10800 1.35                                     30 mins.  68.88    7470        11000 1.48                                     45 mins.  68.65    5620         9920 1.76                                     ______________________________________                                    

EXAMPLE 38 Polymerization of THF withBis(n-cyclopentadienyl)bis(trifluoromethanesulfonato)titanium and AcetylChloride

In a dry box,bis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)titanium (0.50 g)was added to each of three separate oven dried 100 mL RB flasks equippedwith stirring bars. The flasks were sealed with rubber septa and thenremoved from the dry box. Nitrogen bleeds were attached and THF (10 mL)and acetyl chloride (0.375 mL) were added to each flask. After 15, 30,and 45 minutes a polymerization was terminated via the addition of water(25 mL), ether (25 mL) and THF (50 mL). The separated organic phaseswere washed repeatedly with water (3×25 mL), then separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      46.11                                                           30 mins.      66.85                                                           45 mins.      74.97                                                           ______________________________________                                    

EXAMPLE 39 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumand Acetic Anhydride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of three separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedsTHF (20 mL) and acetic anhydride (1.00 mL) were added to each flask.After 15, 30, and 45 minutes, a polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phases were separated, concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  15.22    11300       11900 1.05                                     30 mins.  30.50    18100       20300 1.12                                     45 mins.  39.35    21300       25500 1.20                                     ______________________________________                                    

EXAMPLE 40 Copolymerization of THF and 3-Methyl-THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumand Acetic Anhydride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of three separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedsTHF (7.5 mL), 3-Methyl-THF (2.5 mL) and acetic anhydride (0.10 mL) wereadded to each flask. After 15, 30, and 45 minutes, a polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. ¹ H NMR analysis indicates˜10.5% incorporation of 3-methyl-THF in the polymers. Polymer yields andGPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  24.8      8500        9430 1.11                                     30 mins.  41.15    11400       13300 1.17                                     45 mins.  49.15    12200       15500 1.27                                     ______________________________________                                    

EXAMPLE 41 Preparation ofBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)hafnium

In a dry box, hafnocene dichloride (9.93 g) was dissolved in THF (300mL). To this solution, with stirring, was added a solution of silvertriflate (14.12 g) in THF (100 mL). After 10 minutes the precipitatedsilver chloride was filtered off and the resulting filtrate concentratedto approximately half its volume at reduced pressure. Hexane (250 mL)was added and the resulting mixture placed in the freezer. The resultingprecipitate was filtered and then dried under vacuum. Yield: 10.02 g. ¹H NMR (CDCl₃): 6.68 (s, 10 H), 3.76 (m, 4H), 1.84 (m, 4H).

EXAMPLE 42 Preparation of Bis(pentamethyl-n-cyclopentadienyl)bis(trifluoromethanesulfonato)zirconium

In a dry box, bis(pentamethylcyclopentadienyl)zirconium dichloride(10.00 g) was dissolved in THF (300 mL). To this solution, withstirring, was added a solution of silver triflate (12.46 g) in THF (100mL). After 15 minutes the precipitated silver chloride was filtered offand the resulting filtrate concentrated to approximately half its volumeat reduced pressure. Hexane (250 mL) was added and the resulting mixtureplaced in the freezer. The resulting yellow precipitate was filtered andthen dried under vacuum. Yield: 6.02 g. ¹ H NMR (CDCl₃): 2.12 (s).

EXAMPLE 43 Preparation ofBis(n-cyclopentadienyl)bis(trifluoromethanesulfonato)vanadium

In a dry box, vanadocene dichloride (5.00 g) was dissolved in THF (300mL). To this solution, with stirring, was added a solution of silvertriflate (11.19 g) in THF (100 mL). After 15 minutes the precipitatedsilver chloride was filtered off and the resulting filtrate concentratedto approximately half its volume at reduced pressure. Hexane (250 mL)was added and the resulting mixture placed in the freezer. The resultinggreen precipitate was filtered and then dried under vacuum. Yield: 6.99g.

EXAMPLE 44 Polymerization of THF withbis(n-cyclopentadienyl)tetrahydrofuranbis(trifluoromethanesulfonato)zirconiumand Acetic Anhydride in Hexane

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of three separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedshexane (10 mL), THF (20 mL) and acetic anhydride (0.10 mL) were added toeach flask. After 15, 30, and 45 minutes, a polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields and GPCanalysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  4.96     1390         2020 1.45                                     30 mins.  9.24     2980         3470 1.16                                     45 mins.  20.40    3410         4030 1.18                                     ______________________________________                                    

EXAMPLE 45 Polymerization of Cyclohexene Oxide withbis(n-cyclopentadienyl)tetrahydrofuranbis(trifluoromethanesulfonato)zirconium

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to an oven dried 100 mL RB flask equipped withstirring bar, reflux condenser and addition funnel. The flask was sealedwith a rubber septum and removed from the dry box. After the attachmentof a nitrogen bleed, toluene (10 mL) was added. Then a solution ofcyclohexene oxide (20 mL) and toluene (10 mL) was slowly added via theaddition funnel. After 60 minutes the polymerization was terminated bythe addition of water (25 mL) and toluene (100 mL). The separatedorganic phase was concentrated at reduced pressure and then dried undervacuum. Polymer yield: 2.28 g. GPC analysis (PS STD.): Mn=13600,Mw=24500, PD=1.80.

EXAMPLE 46 Polymerization of THF with Bisn-cyclopentadienyl)tetrahydrofuranbis(trifluoromethanesulfonato)hafniumand Acetic Anhydride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)hafnium(0.50 g) was added to each of four separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedsTHF (10 mL) and acetic anhydride (0.50 mL) were added to each flask.After 15, 30, 45 and 60 minutes, a polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phases were separated, concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  32.13    11200       12200 1.09                                     30 mins.  48.70    15200       18600 1.22                                     45 mins.  58.74    17400       23100 1.33                                     60 mins.  60.54    17000       24100 1.42                                     ______________________________________                                    

EXAMPLE 47 Polymerization of THF withBis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)vanadium andAcetic Anhydride

In a dry box,bis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)vanadium (0.50 g)was added to each of four separate oven dried 100 mL RB flasks equippedwith stirring bars. The flasks were sealed with rubber septa and removedfrom the dry box. After the attachment of nitrogen bleeds THF (10 mL)and acetic anhydride (0.50 mL) were added to each flask. After 15, 30,45 and 60 minutes, a polymerization was terminated via the addition ofwater (25 mL), THF (50 mL) and ether (25 mL). The resulting organicphases were separated, concentrated at reduced pressure and then driedunder vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  17.59    10600       13000 1.22                                     30 mins.  45.32    14100       18800 1.34                                     45 mins.  60.43    15100       21700 1.44                                     60 mins.  62.57    10500       21000 2.00                                     ______________________________________                                    

EXAMPLE 48 Polymerization of THF withBis(Pentamethylcyclopentadienyl)-bis(trifluoromethanesulfonato)zirconiumand Acetic Anhydride

In a dry box,bis(pentamethylcyclopentadienyl)-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to each of four separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand removed from the dry box. After the attachment of nitrogen bleedsTHF (10 mL) and acetic anhydride (0.50 mL) were added to each flask.After 15, 30, 45 and 60 minutes, a polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phases were separated, concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  33.26    10600       11900 1.12                                     30 mins.  44.64    12100       14800 1.23                                     45 mins.  60.09    13400       17600 1.31                                     60 mins.  70.23    15100       20900 1.38                                     ______________________________________                                    

EXAMPLE 49 Polymerization of THF withBis(pentamethylcyclopentadienyl)bis(trifluoromethanesulfonato)zirconiumand Adipoyl Chloride

In a dry box,bis(pentamethylcyclopentadienyl)bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (10 mL) andadipoyl chloride (0.50 mL) were added. After 45 minutes, thepolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 5.87 g (66.17%).

EXAMPLE 50 Polymerization of THF withBis(pentamethylcyclopentadienyl-bis(trifluoromethanesulfonato)zirconiumand Acetyl Bromide

In a dry box,bis(pentamethylcyclopentadienyl)bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (10 mL) andacetyl bromide (0.50 mL) were added. After 45 minutes, thepolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 2.20 g.

EXAMPLE 51 Polymerization of THF withBis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)vanadium andAcetyl Bromide

In a dry box,bis(n-cyclopentadienyl)-bis(trifluoromethanesulfonato)vanadium (0.50 g)was added to an oven dried 100 mL RB flask equipped with a stirring bar.The flask was sealed with rubber septum and removed from the dry box.After the attachment of a nitrogen bleed THF (10 mL) and acetyl bromide(0.50 mL) were added. After 60 minutes, the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 3.68 g.

EXAMPLE 52 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)hafniumand Acetyl Bromide

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)hafnium(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (10 mL) andacetyl bromide (0.50 mL) were added. After 30 minutes, thepolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 2.29 g.

EXAMPLE 53 Polymerization of Oxepane withbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumand Acetic anhydride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.05 g) was added to an oven dried 50 mL RB flask equipped withstirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed oxepane (1.00 mL)and acetic anhydride (0.05 mL) were added via syringe. After 60 minutesthe polymerization was terminated by the addition of water (10 mL) andether (25 mL). The separated organic phase was concentrated at reducedpressure and then dried under vacuum. Polymer yield: 0.87 g.

EXAMPLE 54 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium and Diglycolyl Chloride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethane-sulfonato)zirconium(0.50 g) was added an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (10 mL) anddiglycolyl chloride (1.00 mL) were added to the flask. After 45 minutesthe polymerization was terminated via the addition of water (25 mL), THF(50 mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 0.64 g.

EXAMPLE 55 Copolymerization of THF/3-Methyl-THF withBis(n-cyclopentadienyl)tetrahydrofuranbis(trifluoromethanesulfonato)zirconiumand Diglycolyl Chloride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (7.5 mL),3-methyl-THF (2.5 mL) and diglycolyl chloride (1.00 mL) were added tothe flask. After 45 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 0.63 g.

EXAMPLE 56 Polymerization of THF withBis(pentamethylcyclopentadienyl)-bis(trifluoromethanesulfonato)zirconiumand Trifluoroacetic Anhydride

In a dry box,bis(pentamethylcyclopentadienyl)-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (10 mL) andtrifluoroactic anhydride (0.50 mL) were added. After 3 hrs., thepolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 4.89 g.

EXAMPLE 57 Copolymerization of THF/3-Methyl-THF withBis(n-cyclopentadienyl)tetrahydrofuranbis(trifluoromethanesulfonato)zirconiumand Adipoyl Chloride

In a dry box,bis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconium(0.50 g) was added an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. After the attachment of a nitrogen bleed THF (7.5 mL),3-methyl-THF (2.5 mL) and adipoyl chloride (1.00 mL) were added to theflask. After 60 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 5.98 g.

EXAMPLE 58 Polymerization of THF with Yttrium Triflate and AcetylChloride

In a dry box, yttrium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.

Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30, 45 and 60 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  49.21    1610         3470 2.15                                     30 mins.  50.05    1520         3390 2.22                                     45 mins.  49.77    1510         3570 2.36                                     60 mins.  52.76    1740         3940 2.26                                     ______________________________________                                    

EXAMPLE 59 Polymerization of THF with Ytterbium Triflate and AcetylChloride

In a dry box, ytterbium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.

Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  52.59    1710         3790 2.22                                     30 mins.  52.82    1730         4540 2.61                                     45 mins.  52.25    1730         4690 2.71                                     ______________________________________                                    

EXAMPLE 60 Polymerization of THF with Didymium (Mischmetall) Triflateand Acetyl Chloride

In a dry box, didymium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  21.98    1020         2000 1.95                                     30 mins.  26.94    926          1780 1.92                                     45 mins.  32.86    1040         2060 1.97                                     ______________________________________                                    

EXAMPLE 61 Polymerization of THF with Erbium Triflate and AcetylChloride

In a dry box, erbium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  53.83    1570         3400 2.17                                     30 mins.  56.09    1650         4090 2.47                                     45 mins.  56.99    1710         4310 2.51                                     ______________________________________                                    

EXAMPLE 62 Polymerization of THF with Scandium Triflate and AcetylChloride

In a dry box, scandium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  53.33    1750         4180 2.38                                     30 mins.  54.17    1690         4630 2.73                                     45 mins.  53.49    1570         5660 3.61                                     ______________________________________                                    

EXAMPLE 63 Polymerization of THF with Copper Triflate and AcetylChloride

In a dry box, copper triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.

Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  23.56    101O         2150 2.13                                     30 mins.  31.74    1250         2720 2.18                                     45 mins.  43.24    1390         3180 2.29                                     ______________________________________                                    

EXAMPLE 64 Polymerization of THF with Tin Triflate and Acetyl Chloride

In a dry box, tin triflate (0.75 g) was added to each of three separateoven dried 100 mL RB flasks equipped with stirring bars. The flasks weresealed with rubber septa and then removed from the dry box. Nitrogenbleeds were attached and THF (20 mL) and acetyl chloride (0.75 mL) wereadded to each flask. After 15, 30 and 45 minutes a polymerization wasterminated via the addition of water (25 mL), ether (25 mL) and THF (50mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      23.96                                                           30 mins.      40.53                                                           45 mins.      41.60                                                           ______________________________________                                    

EXAMPLE 65 Polymerization of THF with Zirconium Triflate and AcetylChloride

In a dry box, zirconium triflate (0.75 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetyl chloride (0.75mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  49.04    2040         4320 2.12                                     30 mins.  64.43    2200         4880 2.21                                     45 mins.  65.84    2290         5190 2.27                                     ______________________________________                                    

EXAMPLE 66 Polymerization of THF with Zinc Triflate and Acetyl Chloride

In a dry box, zinc triflate (0.75 g) was added to each of three separateoven dried 100 mL RB flasks equipped with stirring bars. The flasks weresealed with rubber septa and then removed from the dry box. Nitrogenbleeds were attached and THF (20 mL) and acetyl chloride (0.75 mL) wereadded to each flask. After 45, 60 and 75 minutes a polymerization wasterminated via the addition of water (25 mL), ether (25 mL) and THF (50mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      5.64                                                            30 mins.      6.88                                                            45 mins.      7.61                                                            ______________________________________                                    

EXAMPLE 67 Polymerization of THF with Yttrium Triflate and AdipoylChloride

In a dry box, yttrium triflate (1.00 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and adipoyl chloride (1.00mL) were added to each flask. After 15, 30 and 45 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)     Mw   PD                                       ______________________________________                                        15 mins.  56.20    2020         4350 2.16                                     30 mins.  58.62    2350         4790 2.04                                     45 mins.  58.40    1910         5250 2.75                                     ______________________________________                                    

EXAMPLE 68 Polymerization of THF with Terephthaloyl Chloride and YttriumTriflate

In a dry box, yttrium triflate (0.75 g) and terephthaloyl chloride (2.00g) were added to a 100 mL RB flask equipped with a stirring bar. Theflask was sealed with a rubber septum and removed from the dry box. Anitrogen purge was attached and THF (20 mL) added via syringe. After 90minutes the polymerization was terminated by the addition of water (25mL) and THF (25 mL) and ether (50 mL). The separated organic phase wasconcentrated at reduced pressure and then dried under vacuum. Polymeryield:

2.25 g. GPC Analysis (PS STD.): Mn=40900, Mw=63000, PD=1.54.

EXAMPLE 69 Polymerization of THF with Neodymium Triflate and AcetylBromide

In a dry box, neodymium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.Nitrogen bleeds were attached and THF (20 mL) and acetyl bromide (1.50mL) were added to each flask. After 15, 30, 45 and 60 minutes apolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      27.11                                                           30 mins.      27.06                                                           45 mins.      28.13                                                           60 mins.      27.28                                                           ______________________________________                                    

EXAMPLE 70 Polymerization of THF with Diglycolyl Chloride and YtterbiumTriflate

In a dry box, ytterbium triflate (1.00 g) was added to a 100 mL RB flaskequipped with a stirring bar. The flask was sealed with a rubber septumand removed from the dry box. A nitrogen purge was attached and THF (20mL) added via syringe, followed by diglycolyl chloride (2.00 mL, 97%).After 60 minutes the polymerization was terminated by the addition ofwater (25 mL) and THF (25 mL) and ether (50 mL). The separated organicphase was concentrated at reduced pressure and then dried under vacuum.Polymer yield: 9.53 g.

EXAMPLE 71 Polymerization of THF with Diglycolyl Chloride and ZirconiumTriflate

In a dry box, zirconium triflate (1.00 g) was added to a 100 mL RB flaskequipped with a stirring bar. The flask was sealed with a rubber septumand removed from the dry box. A nitrogen purge was attached and THF (20mL) added via syringe, followed by diglycolyl chloride (2.00 mL, 97%).After 60 minutes the polymerization was terminated by the addition ofwater (25 mL) and THF (25 mL) and ether (50 mL). The separated organicphase was concentrated at reduced pressure and then dried under vacuum.Polymer yield: 7.32 g.

EXAMPLE 72 Copolymerization of THF/3-Methyl-THF with Ytterbium Triflateand Adipoyl Chloride

In a dry box, ytterbium triflate (0.50 g) was added an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (7.5 mL), 3-methyl-THF (2.5 mL) and adipoyl chloride(1.00 mL) were added to the flask. After 60 minutes the polymerizationwas terminated via the addition of water (25 mL), THF (50 mL) and ether(25 mL). The resulting organic phase was separated, concentrated atreduced pressure and then dried under vacuum. Polymer yield: 5.2 g.

EXAMPLE 73 Polymerization of THF with Scandium Triflate and AceticAnhydride

In a dry box, scandium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20 mL) and acetic anhydride (0.75mL) were added to each flask. After 15, 30, 45 and 60 minutes, apolymerization was terminated via the addition of water (25 mL) and THF(50 mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields and GPCanalysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        15 mins.  63.64    3780        11000 2.91                                     30 mins.  70.85    3270        9270  2.82                                     45 mins.  70.85    2780        9740  3.49                                     60 mins.  74.18    2930        8330  2.84                                     ______________________________________                                    

EXAMPLE 74 Polymerization of THF with Copper Triflate and AceticAnhydride

In a dry box, copper triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and then removed from the dry box.

Nitrogen bleeds were attached and THF (20 mL) and acetic anhydride (0.75mL) were added to each flask. After 45, 60, 75 and 90 minutes apolymerization was terminated via the addition of water (25 mL) and THF(50 mL). The separated organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields and GPCanalysis:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (%)                                                                              (PS STD)    Mw    PD                                       ______________________________________                                        45 mins.  23.90    10500       21100 2.01                                     60 mins.  30.10    12000       23400 1.95                                     75 mins.  35.00    11400       23500 2.07                                     90 mins.  53.21    13900       25900 1.86                                     ______________________________________                                    

EXAMPLE 75 Polymerization of THF with Zirconium Triflate and Aceticanhydride

In a dry box, zirconium triflate (0.75 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box.Nitrogen bleeds were attached and THF (20 ml) and acetic anhydride (0.75mL) were added to each flask. After 15, 30, 45 and 60 minutes, apolymerization was terminated via the addition of water (25 mL) and THF(50 mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      58.06                                                           30 mins.      65.84                                                           45 mins.      66.91                                                           60 mins.      71.87                                                           ______________________________________                                    

EXAMPLE 76 Polymerization of THF with Tin Triflate and Acetic Anhydride

In a dry box, tin triflate (0.75 g) was added to each of four separateoven dried 100 mL RB flasks equipped with stirring bars. The flasks weresealed with rubber septa and removed from the dry box. Nitrogen bleedswere attached and THF (20 mL) and acetic anhydride (0.75 mL) were addedto each flask. After 15, 30, 45 and 90 minutes, a polymerization wasterminated via the addition of water (25 mL) and THF (50 mL). Theresulting organic phases were separated, concentrated at reducedpressure and then dried under vacuum. Polymer yields:

    ______________________________________                                        Polymer. Time Polymer Yield (%)                                               ______________________________________                                        15 mins.      24.01                                                           30 mins.      44.08                                                           45 mins.      54.68                                                           60 mins.      58.40                                                           ______________________________________                                    

EXAMPLE 77 Polymerization of THF with Zinc Triflate and Acetic Anhydride

In a dry box, zinc triflate (0.75 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (20 mL) and acetic anhydride (0.75 mL) were added.After stirring overnight the polymerization was terminated via theaddition of water (25 mL) and THF (50 mL). The resulting organic phasewas separated, concentrated at reduced pressure and then dried undervacuum. Polymer Yield: 3.17 g (17.87%).

EXAMPLE 78 Depolymerization of Polytetrahydrofuran with Copper Triflate

Polytetrahydrofuran diol, Mn=˜1,000, and copper triflate (9 g) wereplaced in a 500 mL three neck flask equipped with a stirring bar,Vigreaux column (12") and a fractional distillation head. A nitrogenpurge was attached and all other openings were glass stoppered. Theresulting mixture was heated by an oil bath and the resulting waterclear distillate fractions collected as follow:

    ______________________________________                                               Oil Bath   Rxn Temp.  Head Temp.                                                                             Weight                                  Fraction                                                                             Temp (°C.)                                                                        (°C.)                                                                             (°C.)                                                                           (g)                                     ______________________________________                                        1      168        135-139    64       47.85                                   2      168        128-135    64       57.09                                   3      168        118-128    66       53.67                                   4      168        106-128    66       57.77                                   5      168        106        66       76.30                                   ______________________________________                                         Total weight of distillate collected: 292.68 g                                % Yield (Recovery): 97.56%                                                    Total depolymerization time from start of collection to termination of        experiment: 1 hr. 45 mins.                                               

EXAMPLE 79 Copolymerization of THF/3-Methyl-THF with Zirconium Triflateand Acetic Anhydride

In a dry box, zirconium triflate (0.50 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (7.5 mL) and 3-methyl-THF (2.5 mL) were added followedby acetic anhydride (1.00 mL). After 45 minutes the polymerization wasterminated via the addition of water (25 mL) and THF (50 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 5.68 g.

EXAMPLE 80 Copolymerization of THF/3-Methyl-THF with Copper Triflate andAcetic Anhydride

In a dry box, copper triflate (0.50 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (7.5 mL) and 3-methyl-THF (2.5 mL) were added followedby acetic anhydride (1.00 mL). After 60 minutes the polymerization wasterminated via the addition of water (25 mL) and THF (50 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 2.48 g.

EXAMPLE 81 Copolymerization of THF/3-Methyl-THF with Tin Triflate andAcetic Anhydride

In a dry box, tin triflate (0.50 g) was added to an oven dried 100 mL RBflask equipped with a stirring bar. The flask was sealed with a rubberseptum and removed from the dry box. A nitrogen bleed was attached andTHF (7.5 mL) and 3-methyl-THF (1.6 mL) were added followed by aceticanhydride (1.00 mL). After 60 minutes the polymerization was terminatedvia the addition of water (25 mL) and THF (50 mL). The resulting organicphase was separated, concentrated at reduced pressure and then driedunder vacuum. Polymer yield: 4.42 g.

EXAMPLE 82 Copolymerization of THF/3-Methyl-THF with Scandium Triflateand Acetic Anhydride

In a dry box, scandium triflate (0.50 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (7.5 mL) and 3-methyl-THF (2.5 mL) were added followedby acetic anhydride (1.00 mL). After 45 minutes the polymerization wasterminated via the addition of water (25 mL) and THF (50 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 5.81 g.

EXAMPLE 83 Polymerization of THF with Copper Triflate andTrifluoroacetic Anhydride

In a dry box, copper triflate (1.00 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (20 mL) and trifluoroacetic anhydride (2.00 mL) wereadded. After stirring for 3 hrs. the polymerization was terminated viathe addition of water (25 mL) and THF (50 mL). The resulting organicphase was separated, concentrated at reduced pressure and then driedunder vacuum. Polymer Yield: 7.5 g.

EXAMPLE 84 Polymerization of THF with Trifluoroacetic Acid and YtterbiumTriflate at 45° C.

In a dry box, ytterbium triflate (5.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed withrubber septa and removed from the dry box. After the attachment ofnitrogen bleeds THF (20.00 mL) and trifluoroacetic acid (4.00 mL) wereadded to the flask. Then flask was them immediately placed in an oilbath maintained at 45° C. After 120 minutes the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 6.61 g. GPCanalysis (PS STD.): Mn=5680, Mw=9090, PD=1.60.

EXAMPLE 85 Polymerization of THF with Trifluoroacetic Acid and YtterbiumTriflate at 45° C.

In a dry box, ytterbium triflate (5.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed withrubber septa and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) and trifluoroacetic acid (5.00 mL) wereadded to the flask. The flask was then immediately placed in an oil bathmaintained at 45° C. After 120 minutes the polymerization was terminatedvia the addition of water (25 mL), THF (50 mL) and ether (25 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 3.07 g. GPC analysis (PSSTD.): Mn=3290, Mw=4810, PD=1.46.

EXAMPLE 86 Polymerization of THF with Trifluoroacetic Acid and YtterbiumTriflate

In a dry box, ytterbium triflate (2.00, 3.00, 4.00 and 5.00 g) was addedto each of four separate oven dried 100 mL RB flasks equipped withstirring bars. The flasks were sealed with rubber septa and removed fromthe dry box. After the attachment of nitrogen bleeds THF (20.00 mL) andtrifluoroacetic acid (2.00 mL) were added to each flask. After 90minutes the polymerizations were terminated via the addition of water(25 mL), THF (50 mL) and ether (25 mL). The resulting organic phaseswere separated, concentrated at reduced pressure and then dried undervacuum. Polymer yields and GPC analyses:

    ______________________________________                                        Ytterbium Polymer   Mn                                                        Triflate (g)                                                                            Yield (g) (PS STD.)  Mw    PD                                       ______________________________________                                        2.00      5.32      60200      95600 1.59                                     3.00      5.95      58500      89400 1.53                                     4.00      6.70      46100      76700 1.66                                     ______________________________________                                    

EXAMPLE 87 Polymerization of THF with Trifluoroacetic Acid and YttriumTriflate

In a dry box, yttrium triflate (3.00 g) was added to each of threeseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) and trifluoroaceticacid (5.00 mL) were added to each flask. After 120, 150 and 180 minutesa polymerization was terminated via the addition of water (25 mL), THF(50 mL) and ether (25 mL). The resulting organic phases were separated,concentrated at reduced pressure and the n dried under vacuum. Polymeryields and GPC analyses:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (g)                                                                              (PS STD.)    Mw    PD                                      ______________________________________                                        120 mins. 1.57     22700        32900 1.45                                    150 mins. 2.75     24600        37900 1.54                                    180 mins. 3.69     30300        46400 1.54                                    ______________________________________                                    

EXAMPLE 88 Polymerization of THF with Trifluoroacetic Acid and ErbiumTriflate

In a dry box, erbium triflate (4.00 g) was added to each of fiveseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) and trifluoroaceticacid (5.00 mL) were added to each flask. After 60, 90, 120, 150 and 180minutes a polymerization was terminated via the addition of water (25mL), THF (50 mL) and ether (25 mL). The resulting organic phases wereseparated, concentrated at reduced pressure and then dried under vacuum.Polymer yields and GPC analyses:

    ______________________________________                                        Polymer.  Polymer  Mn                                                         Time      Yield (g)                                                                              (PD STD.)    Mw    PD                                      ______________________________________                                         60 mins. 2.02     13300        20900 1.57                                     90 mins. 3.13     26500        36900 1.39                                    120 mins. 4.84     26600        39700 1.49                                    150 mins. 5.08     30600        49600 1.62                                    180 mins. 5.58     27900        45700 1.63                                    ______________________________________                                    

EXAMPLE 89 Copolymerization of THF/3-Methyl-THF with TrifluoroaceticAcid and Ytterbium Triflate

In a dry box, ytterbium triflate (5.00 g) was added to separate ovendried 100 mL RB flasks equipped with stirring bars. The flasks weresealed with rubber septa and removed from the dry box. After theattachment of nitrogen bleeds THF (15.00 mL and 3-methyl-THF (5.00 mL)were added to each flask. Trifluoroacetic acid (3 and 4 mL) was thenadded to each flask. After 120 minutes the polymerizations wereterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phases were separated, concentrated atreduced pressure and then dried under vacuum. Polymer yields and GPCanalyses:

    ______________________________________                                        Trifluoroacetic                                                                           Polymer  Mn                                                       Acid        Yield (g)                                                                              (PS STD.)  Mw    PD                                      ______________________________________                                        3 mL        5.37     24500      37500 1.53                                    4 mL        3.9      20900      30300 1.45                                    ______________________________________                                    

EXAMPLE 90 Polymerization of THF with TrifluoroaceticAnhydride/Trifluoroacetic Acid and Ytterbium Triflate

In a dry box, ytterbium triflate (3.00 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) was added to eachflask. Trifluoroacetic anhydride and trifluoroacetic acid were addedtogether via syringes in the ratios shown below. After 60 minutes thepolymerizations were terminated via the addition of water (25 mL), THF(50 mL) and ether (25 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analyses:

    ______________________________________                                        Trifluoroacetic Anhydride/                                                                  Polymer  Mn                                                     Trifluoroacetic Acid (mL)                                                                   Yield (g)                                                                              (PS STD.) Mw    PD                                     ______________________________________                                        5/2           10.66    8090      13400 1.66                                   5/3           9.21     6600      10100 1.54                                   5/4           7.13     5200       8150 1.57                                   5/5           4.86     4200      59100 1.41                                   ______________________________________                                    

EXAMPLE 91 Polymerization of THF with TrifluoroaceticAnhydride/Trifluoroacetic Acid and Ytterbium Triflate

In a dry box, ytterbium triflate (3.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) was added to the flask. Trifluoroaceticanhydride (3.00 mL) and trifluoroacetic acid (5.00 mL) were addedtogether via syringe. After 60 minutes the polymerization was terminatedvia the addition of water (25 mL), THF (50 mL) and ether (25 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 6.85 g. GPC analysis:Mn=5910, Mw=9970, PD=1.50 (PS STD.).

EXAMPLE 92 Polymerization of THF with Pentafluoropropionic Acid andYtterbium Triflate

In a dry box, ytterbium triflate (5.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) and pentafluoropropionic acid (2.00 mL)were added via syringe. After 150 minutes the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25ml). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 9.42 g. GPCanalysis: Mn=71500, Mw=126000, PD=1.77 (PS STD.).

EXAMPLE 93 Polymerization of THF with Pentafluoropropionic Acid andYtterbium Triflate

In a dry box, ytterbium triflate (5.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) and pentafluoropropionic acid (5.00 mL)were added via syringe. After 150 minutes the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 7.00 g. GPCanalysis: Mn=20100, Mw=38700, PD=1.92 (PS STD.).

EXAMPLE 94 Polymerization of THF with Cyanoacetic Acid and YtterbiumTriflate

In a dry box, ytterbium triflate (5.00 g) and cyanoacetic acid (5.00 g)were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with a rubber septum and removed from the drybox. After the attachment of a nitrogen bleed THF (20.00 mL) was addedvia syringe. After 150 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 6.15 g. GPC analysis: Mn=22900,Mw=33900, PD=1.48 (PS STD.).

EXAMPLE 95 Polymerization of THF with Trifluoroacetic Acid and AluminumTriflate

In a dry box, aluminum triflate (1.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (10 mL) and trifluoroacetic acid (1.5 mL) were addedvia syringe. After 120 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 4.17 g. GPC analysis: Mn=28500,Mw=52000, PD=1.82 (PS STD.).

EXAMPLE 96 Polymerization of THF with Trifluoroacetic Acid and ZirconiumTriflate

In a dry box, zirconium triflate (1.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (10 mL) and trifluoroacetic acid (1.5 mL) were addedvia syringe. After 120 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 5.63 g. GPC analysis: Mn=33300,Mw=52600, PD=1.58 (PS STD.).

EXAMPLE 97 Polymerization of THF with Pentafluoropropionic Acid andAluminum Triflate

In a dry box, aluminum triflate (2.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (10.00 mL) and pentafluoropropionic acid (0.90 mL)were added via syringe. After 120 minutes the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 6.73 g. GPCanalysis: Mn=11700, Mw=20600, PD=1.76 (PS STD.).

EXAMPLE 98 Polymerization of THF with Chlorodifluoroacetic Acid andZirconium Triflate

In a dry box, zirconium triflate (2.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (10.00 mL) and chlorodifluoroacetic acid (2.50 mL)were added via syringe. After 120 minutes the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer yield: 5.55 g. GPCanalysis: Mn=19600, Mw=35300, PD=1.80 (PS STD.).

EXAMPLE 99 Polymerization of THF with 4-Nitrobenzoic Acid and AluminumTriflate

In a dry box, aluminum triflate (1.50 g) and 4-nitrobenzoic acid (4.50g) were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with a rubber septum and removed from the drybox. After the attachment of a nitrogen bleed THF (20.00 mL) was addedvia syringe. After 30 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was washed with water (2×1000 mL), separated, concentratedat reduced pressure and then dried under vacuum. Polymer yield: 4.43 g.GPC analysis: Mn=37000, Mw=51000, PD=1.38 (PS STD.).

EXAMPLE 100 Polymerization of THF with Trifluoroacetic Acid and YttriumTriflate

In a dry box, yttrium triflate (3.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) and trifluoroacetic acid (5.00 mL) wereadded via syringe. After 180 minutes the polymerization was terminatedvia the addition of water (25 mL), THF (50 mL) and ether (25 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 3.69 g. GPC analysis:Mn=30300, Mw=46400, PD=1.54 (PS STD.).

EXAMPLE 101

Copolymerization of THF/3-Methyl-THF with Trifluoroacetic Acid andYtterbium Triflate

In a dry box, ytterbium triflate (5.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (15.00 mL), 3-methyl-THF (5.00 mL) andtrifluoroacetic acid (3.00 mL) were added via syringe. After 120 minutesthe polymerization was terminated via the addition of water (25 mL), THF(50 mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 5.37 g. GPC analysis: Mn=24500, Mw=37500, PD=1.53 (PS STD.).

EXAMPLE 102 Polymerization of THF with Acetic Acid and YtterbiumTriflate

In a dry box, ytterbium triflate (5.00 g) was added to each of fourseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) and acetic acid (5.00mL) were added to each flask. After 3, 4, 5 and 24 hours apolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phases were separated,washed with water (2×50 mL), concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analyses:

    ______________________________________                                        Polymer.   Polymer  Mn                                                        Time (Hrs.)                                                                              Yield (g)                                                                              (PS STD.)  Mw    PD                                       ______________________________________                                        3          1.15     17900      34600 1.93                                     4          1.38     18400      33700 1.83                                     5          1.71     16400      34000 2.07                                     24         5.29     13000      30400 2.33                                     ______________________________________                                    

EXAMPLE 103 Polymerization of THF with Formic Acid (96%) Acid andYtterbium Triflate

In a dry box, ytterbium triflate (5.00 g) was added to each of sixseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) and formic acid (96%,0.75 mL) were added to each flask. After 2, 3, 4, 5, 6 and 24 hours apolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phases were separated,washed with water (2×50 mL), concentrated at reduced pressure and thendried under

    ______________________________________                                        Polymer.   Polymer  Mn                                                        Time (Hrs.)                                                                              Yield (g)                                                                              (PS STD.)  Mw    PD                                       ______________________________________                                        2          1.25     14300      29500 2.06                                     3          1.65     15100      30300 2.00                                     4          2.27     17600      32700 1.88                                     5          2.72     16700      30800 1.85                                     6          3.29     15300      29800 1.95                                     24         7.93     10700      23100 2.16                                     ______________________________________                                    

EXAMPLE 104 Polymerization of THF with Formic Acid (96%) Acid andYtterbium Triflate

In a dry box, ytterbium triflate (15.77 g) was added to each of sixseparate oven dried 100 mL RB flasks equipped with stirring bars. Theflasks were sealed with rubber septa and removed from the dry box. Afterthe attachment of nitrogen bleeds THF (20.00 mL) and formic acid (96%,2.00 mL) were added to each flask. After 3, 4, 5, 6 and 24 hours apolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phases were separated,washed with water (2×50 mL), concentrated at reduced pressure and thendried under vacuum. Polymer yields and GPC analyses:

    ______________________________________                                        Polymer.   Polymer  Mn                                                        Time (Hrs.)                                                                              Yield (g)                                                                              (PS STD.)  Mw    PD                                       ______________________________________                                        2          1.67     4350       10900 2.51                                     3          2.22     5560       12000 2.16                                     4          2.83     5320       12400 2.34                                     5          3.09     5460       12100 2.22                                     6          3.28     5390       11700 2.19                                     24         5.82     3050        7860 2.58                                     ______________________________________                                    

EXAMPLE 105 Polymerization of THF with Pyruvonitrile and YtterbiumTriflate

In a dry box, ytterbium triflate (3.00 g) was added to a 100 mL roundbottom flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) was added followed by pyruvonitrile (95%,2.00 mL). After 60 minutes the polymerization was terminated by theaddition of water (10 mL), THF (25 mL) and diethyl ether (25 mL). Theresulting organic phase was separated, concentrated at reduced pressureand then dried under vacuum. Polymer yield: 1.44 g. GPC analysis:Mn=52700, Mw=67000, PD=1.27 (PS STD.).

EXAMPLE 106 Polymerization of THF with Acetic Acid/Acetic Anhydride andYttrium Triflate

In a dry box, yttrium triflate (1.00 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL), acetic acid (2.00 mL) and aceticanhydride (2.00 mL) were added via syringe. After 60 minutes thepolymerization was terminated via the addition of water (25 mL), THF (50mL) and ether (25 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 7.32 g. GPC analysis: Mn=2470, Mw=5250, PD=2.13 (PS STD.).

EXAMPLE 107 Polymerization of THF with Trichloroacetic Acid and AluminumTriflate

In a dry box, aluminum triflate (4.5 g) and trichloroacetic acid (4.5 g)were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with a rubber septum and removed from the drybox. After the attachment of a nitrogen bleed THF (10.00 mL) was addedvia syringe. After 120 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was washed with water (2×50 mL), separated, concentratedat reduced pressure and then dried under vacuum. Polymer yield: 5.0 g.GPC analysis: Mn=33500, Mw=80100, PD=2.39 (PS STD.).

EXAMPLE 108 Polymerization of THF with 11-Cyano-1-undecanoic Acid andYtterbium Triflate

In a dry box, ytterbium triflate (10.00 g) and 11-cyano-1-undecanoicacid (5.00 g) were added to an oven dried 100 mL RB flask equipped witha stirring bar. The flask was sealed with a rubber septum and removedfrom the dry box. After the attachment of a nitrogen bleed THF (20.00mL) was added via syringe. After 6 hrs. the polymerization wasterminated via the addition of water (25 mL), THF (50 mL) and ether (25mL). The resulting organic phase was separated, washed with 5% sodiumbicarbonate (2×25 mL), concentrated at reduced pressure and then driedunder vacuum. Polymer yield: 5.61 g.

EXAMPLE 109 Polymerization of THF with 4-Acetylbutyric Acid andYtterbium Triflate

In a dry box, ytterbium triflate (10.00 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. After the attachment of anitrogen bleed THF (20.00 mL) and 4-acetylbutyric (1.00 mL) were addedvia syringe. After 90 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, washed with 5% sodium bicarbonate (2×25mL), concentrated at reduced pressure and then dried under vacuum.Polymer yield: 3.25 g.

EXAMPLE 110 Polymerization of THF with Glycolic Acid and YtterbiumTriflate

In a dry box, ytterbium triflate (10.00 g) and glycolic acid (99%, 1.00g) were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with a rubber septum and removed from the drybox. After the attachment of a nitrogen bleed THF (20.00 mL) was addedvia syringe. After 90 minutes the polymerization was terminated via theaddition of water (25 mL), THF (50 mL) and ether (25 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer yield: 4.76 g.

EXAMPLE 111 Preparation of Bismuth Triflate

BiCl₃ (630 mg, 2 mmol) was slurried in CH₂ Cl₂ (20 mL). Triflic acid(900 mg, 6 mmol) was added dropwise, and the mixture was stirredovernight at room temperature. The solvent was removed to give 0.9 g ofan off white solid. ¹⁹ F NMR (DMSO-d₆): δ-77.3.

EXAMPLE 112 Polymerization of THF with Bismuth Triflate and AceticAnhydride

In a dry box, bismuth triflate (0.5 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 5.71 g. GPC analysis: Mn=8350,Mw=12400, PD=1.49 (PS STD.).

EXAMPLE 113 Preparation of Zr(OSO₂ CF₃)₄.Zr(OCOCH₃)₄

Solid Zr(OTf)₄ (0.5 g) and Zr(CF₃ CO₂)₄ (0.5 g) were mixed and THF (25mL) was added. The mixture was stirred for 15 minutes at roomtemperature. The solvent was removed and 0.9 g of off white solid wascollected. ¹⁹ F NMR (CDCl₃): δ-78.3, -76.2 (Zr(CF₃ CO₂)₄ comes atδ-75.8).

EXAMPLE 114 Polymerization of THF with Zr(OSO₂ CF₃)₄.Zr(OCOCH₃)₄ andAcetic Anhydride

In a dry box, Zr(OSO₂ CF₃)₄.Zr(OCOCH₃)₄ (0.5 g) was added to an ovendried 100 mL RB flask equipped with a stirring bar. The flask was sealedwith a rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 5.01 g. GPC analysis: Mn=6900,Mw=10500, PD=1.53 (PS STD.).

EXAMPLE 115 Preparation of Gold Triflate

AuBr₃ (0.90 g, 2.1 mmol) was slurried in CH₂ Cl₂ (20 mL) and triflicacid (0.90 g, 6.3 mmol) was added dropwise. The mixture was stirredovernight at room temperature. The solvent was removed and 0.77 g ofblack solid was collected. ¹⁹ F NMR (DMSO-d₆): δ-76.9.

EXAMPLE 116 Polymerization of THF with Gold(III) Triflate and AceticAnhydride

In a dry box, gold(III) triflate (0.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 6.04 g. GPC analysis: Mn=5240,Mw=9060, PD=1.73 (PS STD.).

EXAMPLE 117 Preparation of Y(OSO₂ CF₃)₂ Cl

Solid Y(OTf)₃ (540 mg, 1 mmol) and YCl₃ (98 mg, 0.5 mmol) were mixed,and this mixture was poured into stirred THF (30 mL). The mixture becamewarm as the solid dissolved. The solution was stirred for 15 min, andthe THF was removed. ¹⁹ F NMR (DMSO-d₆): δ-77.3.

EXAMPLE 118 Polymerization of THF with Y(OSO₂ CF₃)₂ Cl and AceticAnhydride

In a dry box, Y(OSO₂ CF₃)₂ Cl (0.5 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 2.95 g. GPC analysis: Mn=7390,Mw=12800, PD=1.73 (PS STD.).

EXAMPLE 119

Preparation of Y(OSO₂ CF₃)Cl₂

Solid Y(OTf)₃ (540 mg, 1 mmol) and YCl₃ (390 mg, 2 mmol) were mixed, andthis mixture was poured into stirred THF (30 mL). The mixture becamewarm as the solid dissolved. The solution was stirred for 15 min, andthe THF was removed. ¹⁹ F NMR (DMSO-d₆): δ-77.2

EXAMPLE 120 Polymerization of THF with Y(OSO₂ CF₃)Cl₂ and AceticAnhydride

In a dry box, Y(OSO₂ CF₃)Cl₂ (0.5 g) was added to an oven dried 100 mLRB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 0.09 g.

EXAMPLE 121 Preparation of Ta(OSO₂ CF₃)₄ OCH₂ CH₃

Ta(OEt)₅ (813 mg, 2 mmol) was dissolved in CH₂ Cl₂ (20 mL). Triflic acid(1.5 g, 10 mol) was added dropwise and the solution stirred overnight atroom temperature. The solvent was removed to produce a colorless oil. ¹H and ¹⁹ F NMR show a mixture of compounds. ¹ H NMR (CDCl₃): δ1.85 (t),1.9 (t), 4.1, (q), 4.15 (broad, q).

EXAMPLE 122 Polymerization of THF with Ta(OSO₂ CF₃)₄ OCH₂ CH₃ and AceticAnhydride

In a dry box, Ta(OSO₂ CF₃)₄ OCH₂ CH₃ (0.5 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL), and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 6.29 g. GPC analysis: Mn=2320,Mw=5400, PD=2.33 (PS STD.).

EXAMPLE 123 Preparation of Iron(III) Bis-triflate-acetylacetonate

Fe(acac)₃ (1.0 g, 2.8 mmol) was dissolved in CH₂ Cl₂ (15 mL), andtriflic acid (850 mg, 5.7 mmol) was added dropwise. The purple solutionwas stirred overnight at room temperature. The solvent was removed togive a dark oil.

EXAMPLE 124 Polymerization of THF with Iron(III)Bis-Triflate-Acetylacetonate and Acetic Anhydride

In a dry box, iron(III) bis-triflate-acetylacetonate (0.5 g) was addedto an oven dried 100 mL RB flask equipped with a stirring bar. The flaskwas sealed with a rubber septum and removed from the dry box. A nitrogenbleed was attached and THF (10.00 mL) and acetic anhydride (1.00 mL)were added. After stirring for 60 minutes the polymerization wasterminated via the addition of water (25 mL), ether (25 mL) and THF (50mL). The resulting organic phase was separated, concentrated at reducedpressure and then dried under vacuum. Polymer Yield: 5.63 g. GPCanalysis: Mn=8330, Mw=16100, PD=1.94 (PS STD.).

EXAMPLE 125 Preparation of Ruthenium(III) Triflate

RuCl₃ (1.0 g, 4.6 mmol) was slurried in CH₂ Cl₂ (20 m%) and triflic acid(2.0 g, 13.6 mmol) was added dropwise. The mixture was stirred at roomtemperature overnight. The solvent was removed and 1.15 g of black solidwas collected. ¹⁹ F NMR (CDCl₃): δ-76.7.

EXAMPLE 126 Polymerization of THF with Ruthenium(III) Triflate andAcetic Anhydride

In a dry box, ruthenium(III) triflate (0.5 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 30 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 5.25 g. GPC analysis: Mn=7960,Mw=12400, PD=1.56 (PS STD.).

EXAMPLE 127 Preparation of Palladium(II) Triflate

PdCl₂ (1.0 g, 5.6 mmol) was slurried in CH₂ Cl₂ (20 mL) and triflic acid(1.7 g, 11.3 mmol) was added dropwise. The mixture was stirred at roomtemperature overnight. The solvent was removed and 0.9 g of rust colorsolid was collected. ¹⁹ F NMR (CDCl₃): δ-78.5.

EXAMPLE 128 Polymerization of THF with Palladium(II) Triflate and AceticAnhydride

In a dry box, palladium(II) triflate (0.5 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 0.73 g. GPC analysis: Mn=27100,Mw=32500, PD=1.20 (PS STD.).

EXAMPLE 129 Polymerization of THF with Niobium(V) Triflate and AceticAnhydride

In a dry box, niobium(V) triflate (0.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 6.41 g. GPC analysis: Mn=1580,Mw=5810, PD=3.67 (PS STD.).

EXAMPLE 130 Polymerization of THF with Tungsten(VI) Triflate and AceticAnhydride

In a dry box, tungsten(VI) triflate (0.5 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 6.12 g. GPC analysis: Mn=4430,Mw=833b, PD=1.88 (PS STD.).

EXAMPLE 131 Preparation of Rhenium(V) Triflate.

ReCl₅ (1.0 g, 2.75 mmol) was slurried in CH₂ Cl₂ (25 mL) and triflicacid (2.1 g, 13.7 mmol) was added dropwise. The mixture was stirredovernight at room temperature. The solvent was removed and 0.9 g ofblack solid was collected. ¹⁹ F NMR (CDCl₃): δ-74.4, -76.3 (small peak).

EXAMPLE 132 Polymerization of THF with Rhenium(V) Triflate and AceticAnhydride

In a dry box, rhenium(V) triflate (0.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 5.60 g. GPC analysis: Mn=7170,Mw=13500, PD=1.89 (PS STD.).

EXAMPLE 133 Preparation of Chromium(II) Triflate

CrCl₂ (0.62 g, 5 mmol) was slurried in CH₂ Cl₂ (20 mL) and triflic acid(2.3 g, 15 mmol) was added dropwise. The mixture was stirred overnightat room temperature. The solvent was removed and 1.25 g of gray solidwas collected. ¹⁹ F NMR (DMSO-d₆): δ-76.65, -76.72.

EXAMPLE 134 Polymerization of THF with Chromium(II) Triflate and AceticAnhydride

In a dry box, chromium(II) triflate (0.5 g) was added to an oven dried100 mL RB flask equipped with a stirring bar. The flask was sealed witha rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 4.87 g. GPC analysis: Mn=9210,Mw=18800, PD=2.05 (PS STD.).

EXAMPLE 135 Preparation ofn--Cyclopentadienyl-tris(trifluoromethanesulfonato)zirconium

Cp*ZrCl₃ (1.0 g, 3 mmol) was slurried in CH₂ Cl₂ (40 mL). THF (10.00 mL)was added to dissolve the yellow solid. Solid AgOTf (2.3 g, 9 mmol) wasadded; a white solid formed immediately. The mixture was stirred 15 min,and the orangish solution was filtered. The solvent was removed toproduce an orangish oil. The material was crystallized from ether and1.1 g of yellow solid was collected. ¹ H NMR showed several peaks around2 ppm. Coordinated THF is observed by ¹ H NMR (near δ3.5 and 1.2).

EXAMPLE 136 Polymerization of THF withn-pentamethylcyclopentadienyl-tris-(trifluoromethanesulfonato)zirconiumand Acetic Anhydride

In a dry box,n-pentamethylcyclopentadienyl-tris(trifluoromethanesulfonato)zirconium(0.5 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (10.00 mL) and aceticanhydride (1.00 mL) were added. After stirring for 60 minutes thepolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. PolymerYield: 6.49 g. GPC analysis: Mn=4350, Mw=7930, PD=1.82 (PS STD.).

EXAMPLE 137 Preparation of Strontium Triflate

SrCl₂ (790 mg, 5 mmol) was slurried in CH₂ Cl₂ (20 mL) and triflic acid(1.5 g, 10 mmol) was added dropwise. The mixture was stirred overnightat room temperature. The solvent was removed and 1.7 g of white solidwas collected. ¹⁹ F NMR (DMSO-d₆): δ-77.4.

EXAMPLE 138 Polymerization of THF with Strontium Triflate and AceticAnhydride

In a dry box, strontium triflate (0.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL.) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 5.44 G. GPC analysis: Mn=6630,Mw=11500, PD=1.73 (PS STD.).

EXAMPLE 139 Preparation of Cp₂ (OTf)Zr--O--Zr(OTf)Cp₂

Cp₂ Zr(Cl)--O--(Cl)ZrCp₂ (1.3 g, 2.5 mmol) was dissolved in CH₂ Cl₂ (40mL), and AgOTf (1.3 g, 5 mmol) was added. The mixture was stirred over aweekend. The mixture was filtered and the solvent was removed. A whitesolid formed as the solvent evaporated. The mixture was filtered and thesolid was washed with Et₂ O. 1.4 g of white solid was collected. ¹ H NMR(toluene-d₈): δ6.0 (s).

EXAMPLE 140 Polymerization of THF with Cp₂ (OTf)Zr--O--Zr(OTf)Cp₂ andAcetic Anhydride

In a dry box, Cp₂ (OTf)Zr--O--Zr(OTf)Cp₂ (0.5 g) was added to an ovendried 100 mL RB flask equipped with a stirring bar. The flask was sealedwith a rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 1.84 g. GPC analysis: Mn=22600,Mw=28800, PD=1.28 (PS STD.).

EXAMPLE 141 Polymerization of THF with Cp₂ MeZr(THF)BPh₄ and AceticAnhydride

In a dry box, Cp₂ MeZr(THF)BPh₄ (0.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 0.78 g. GPC analysis: Mn=4840,Mw=7390, PD=1.53 (PS STD.).

EXAMPLE 142 Preparation ofBis-(n-Cyclopentadienyl)bis(trifluoromethanesulfonato)molybdenum

Solid Cp₂ MoCl₂ (500 mg, 1.7 mmol) and AgOTf (0.91 g, 3.5 mmol) weremixed and CH₂ Cl₂ (30 mL). The mixture stirred overnight at roomtemperature. The white solid was filtered off and the solvent wasevaporated to give 300 mg of a green solid. ¹ H NMR (CDCl₃): δ6.4 (s).

EXAMPLE 143 Polymerization of THF withBis-(n-Cyclopentadienyl)bis-(trifluoromethanesulfonato)molybdenum andAcetic Anhydride

In a dry box,bis-(n-Cyclopentadienyl)-bis-(trifluoromethanesulfonato)molybdenum(0.275 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (10.00 mL) and aceticanhydride (1.00 mL) were added. After stirring for 60 minutes thepolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. PolymerYield: 0.77 g. GPC analysis: Mn=15000, Mw=21600, PD=1.44 (PS STD.).

EXAMPLE 144 Preparation ofBis(trifluoromethanesulfonato)-bis(acetylacetonate)zirconium

Zr(acac)₄ (1.46 g, 3 mmol) was dissolved in CH₂ Cl₂ (5 mL). A solutionof triflic acid (0.9 g, 6 mmol) in CH₂ Cl₂ (1 mL) was added to theZr(acac)₄ solution. The solution was stirred 2 hours at roomtemperature. The solvent was removed and 1.79 g of yellow solid wascollected. ¹⁹ F NMR (CDCl₃): δ-78.4; ¹ H NMR (CDCl₃): δ2.15 (s), 5.82(broad).

EXAMPLE 145 Polymerization of THF withBis(trifluoromethanesulfonato)-bis(acetylacetonate)zirconium and AceticAnhydride

In a dry box,bis(trifluoromethanesulfonato)bis(acetylacetonate)zirconium (0.50 g) wasadded to an oven dried 100 mL RB flask equipped with a stirring bar. Theflask was sealed with a rubber septum and removed from the dry box. Anitrogen bleed was attached and THF (10.00 mL) and acetic anhydride(1.00 mL) were added. After stirring for 60 minutes the polymerizationwas terminated via the addition of water (25 mL), ether (25 mL) and THF(50 mL). The resulting organic phase was separated, concentrated atreduced pressure and then dried under vacuum. Polymer Yield: 5.27 g. GPCanalysis: Mn=13400, Mw=20200, PD=1.51 (PS STD.).

EXAMPLE 146 Preparation of YttriumBis(trifluoromethanesulfonato)-2,2,6,6-tetramethyl-3,5-heptanedionate

(t-Buacac)₃ Y (0.64 g, 1 mmol) was dissolved in CH₂ Cl₂ (5 mL). Asolution of triflic acid (0.3 g, 2 mmol) in CH₂ Cl₂ (1 mL) was added andthe solution was stirred 2 hours at room temperature. The solvent wasremoved and a white solid was collected. ¹ H NMR (CDCl₃): δ1.2, 1.1(broad s); ¹⁹ F NMR (CDCl₃): δ-78.4.

EXAMPLE 147 Polymerization of THF with YttriumBis(trifluoromethanesulfonato)-2,2,6,6-tetramethyl-3,5-heptanedionateand Acetic Anhydride

In a dry box, yttriumbis(trifluoromethanesulfonato)-2,2,6,6-tetramethyl-3,5-heptanedionate(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (10.00 mL) and aceticanhydride (1.00 mL) were added. After stirring for 60 minutes thepolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. PolymerYield: 1.26 g. GPC analysis: Mn=17200, Mw=25300, PD=1.47 (PS STD.).

EXAMPLE 148 Preparation of YttriumTrifluoromethanesulfonato-bis(2,2,6,6-tetramethyl-3,5-heptanedionate)

(t-Buacac)₃ Y (0.64 g, 1 mmol) was dissolved in CH₂ Cl₂ (5 mL). Asolution of triflic acid (0.15 g, 1 mmol) in CH₂ Cl₂ (1 mL) was addeddropwise and the solution was stirred 2 h at room temperature. Thesolvent was removed and a white solid was collected. ¹ H NMR (CDCl₃):δ1.15, 1.02; ¹⁹ F NMR (CDCl₃): δ-78.6 (small, broad), -76.7.

EXAMPLE 149 Polymerization of THF with YttriumTrifluoromethanesulfonato-bis(2,2,6,6,6-tetramethyl-3,5-heptanedionate)and Acetic Anhydride

In a dry box, yttriumtrifluoromethanesulfonato-bis(2,2,6,6-tetramethyl-3,5-heptanedionate)(0.50 g) was added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (10.00 mL) and aceticanhydride (1.00 mL) were added. After stirring for 60 minutes thepolymerization was terminated via the addition of water (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phase was separated,concentrated at reduced pressure and then dried under vacuum. PolymerYield: 0.18 g.

EXAMPLE 150 Preparation of VO(OTf)_(n) (OCHMe₂)_(3-n)

V(O)(OnPr)₃ (1.2 g, 5 mmol) was dissolved in CH₂ Cl₂ (30 mL). Triflicacid (2.2 g, 15 mmol) was added dropwise to produce a dark red solution.The solvent was removed and a dark oil was produced.

EXAMPLE 151 Polymerization of THF with VO(OTf)_(n) (OCHMe₂)_(3-n) andAcetic Anhydride

In a dry box, VO(OTf)_(n) (OCHMe₂)_(3-n) (0.50 g) was added to an ovendried 100 mL RB flask equipped with a stirring bar. The flask was sealedwith a rubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 6.07 g. GPC analysis.: Mn=4770,Mw=29110, PD=1.91 (PS STD.).

EXAMPLE 152 Preparation of Silicon Triflate

SiCl₄ (3 g, 17.6 mmol) was dissolved in CH₂ Cl₂ (75 mL) and triflic acid(10.6 g, 70.7 mmol) was added dropwise. The mixture was stirred at roomtemperature over the weekend. The solvent was removed and 4.8 g of brownliquid was collected. ¹⁹ F NMR (DMSO-d₆): δ-76.4 (intense), small broadpeaks at -77.8 and -77.95.

EXAMPLE 153 Polymerization of THF with Silicon Triflate and AceticAnhydride

In a dry box, silicon triflate (0.50 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. A nitrogen bleed wasattached and THF (10.00 mL) and acetic anhydride (1.00 mL) were added.After stirring for 60 minutes the polymerization was terminated via theaddition of water (25 mL), ether (25 mL) and THF (50 mL). The resultingorganic phase was separated, concentrated at reduced pressure and thendried under vacuum. Polymer Yield: 7.76 g. GPC analysis: Mn=1450,Mw=3170, PD=2.18 (PS STD.).

EXAMPLE 154 Polymerization of 1,3-Dioxolane with Ytterbium Triflate

In a dry box,ytterbium triflate (1.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. The flask was sealed with arubber septum and removed from the dry box. After the attachment ofnitrogen bleeds 1,3-dioxolane (10.00 mL) was added to the flask. After60 minutes the polymerization was terminated via the addition of water(25 mL), THF (50 mL) and ether (25 mL). The resulting aqueous phase wasseparated, concentrated at reduced pressure and then dried under vacuum.Yield: 8.89 g (no attempt was made to remove the catalyst from thepolymer). GPC analysis (PS STD.): Mn=4170, Mw=8550, PD=2.05.

EXAMPLE 155 Polymerization of 1,3,5-Trioxane with Ytterbium Triflate

In a dry box, ytterbium triflate (1.5 g) was added to an oven dried 100mL RB flask equipped with a stirring bar. In a separate 100 mL RB flask1,3,5-trioxane (20.00 g) was added. The flasks were sealed with a rubberseptum and removed from the dry box. To the flask containing thetrioxane cyclohexane (20 mL) was added, and the resulting mixtureheating to 60° C. via an oil bath until an homogeneous solutionresulted. This solution (20.00 mL) was then added via syringe to theflask with ytterbium triflate at this temperature. The resulting mixturewas then placed in an oil bath maintained at 60° C. After 60 minutes,the polymerization was terminated by the addition of water (25 mL) andether (25 mL). The resulting solid was separated and dried under vacuum,giving 4.74 g of polymer.

EXAMPLE 156 Heterogeneous 10 wt % Yttrium triflate on alumina catalystpreparation

25 g commercial alumina pellets AL-3945 (3.2 mm dia×3.2 mm) was placedin 250 mL water and the pH adjusted to 3 with acetic acid. Afterstirring 15 mins the pellets were collected by filtration and suctiondried. A solution of 190 mL ethanol and 10 mL water had its apparent pHadjusted to 5 with acetic acid and 5 g of DETM was added. After stirringfor 5 minutes the alumina pellets were added and agitated for 30minutes. The supernatant liquid was then decanted and the pellets washedwith 2×25 mL ethanol and suction dried. The solid was dried in flowingnitrogen by heating to 110° C. for 1 hour and then sealed and taken intoa nitrogen glove box. 5 g yttrium triflate was dissolved in 50 mLacetonitrile and added to the dry alumina pellets. This slurry wasallowed to sit undisturbed overnight in the glove box and thenevaporated to dryness in vacuo. The solid was then extracted with 2×25mL acetonitrile, filtered and washed with acetonitrile. Evaporation ofall washings and extracts indicated that ˜50% of the original yttriumtriflate had been retained on the pellets. The pellets were suctiondried and then dried in flowing nitrogen at 110° C. for 1 hour beforereturning to the glove box for collection and storage prior to testing.

EXAMPLE 157 Polymerization of THF over 10% Yttrium Triflate on AluminaPellets with Acetic Anhydride

THF was charged into a 500 mL capacity ISCO pump, which was connected toa 3 way 0.3 cm SS connector ("T" mixer) via 8 cm of 0.3 cm SS tubingcontaining a check valve. A second ISCO pump was charged with aceticanhydride and this was connected to the "T" mixer by 75 cm of 0.3 cm SStubing also containing a check valve.

In a dry box, all of the catalyst made in Example 1 (23.9 g) was chargedinto the reactor. This was in turn connected to the "T" mixer by 12 cmof SS tubing. This reactor was then connected to a holdup tank(approximately 60 mL volume) via Cajon flex tubing with ultra torrfitting (0.6 cm, 13 cm. Polymerization was started by first filling thereactor with THF (approximately 83 mL). Then THF was fed at a rate of0.75 mL/min and acetic anhydride at a rate of 0.075 mL/min. The exitingpolymerized solution was fed to a beaker. After each fraction, the pumpswere refilled and the collected polymer solution diluted with diethylether and washed with water, separated, concentrated at reduced pressureand then dried under vacuum. The following are the conditions underwhich the various fractions were collected, together with weight ofpolymer obtained and GPC analysis:

    __________________________________________________________________________             THF  ACA                                                                 Polymer.                                                                           Flow Rate                                                                          Flow Rate                                                                           Wt.                                                                              Mn                                                     Fraction                                                                          Time (mL/min)                                                                           (mL/min)                                                                            (g)                                                                              (PS STD.)                                                                           Mw  PD                                           __________________________________________________________________________    1   372 mins.                                                                          0.75 0.075 108.9                                                                            10800 22800                                                                             2.11                                         2   899 mins.                                                                          0.50 0.05  139.2                                                                            15800 36800                                                                             2.32                                         3   491 mins.                                                                          0.50 0.05  17.73                                                                            27400 92300                                                                             3.37                                         4   975 mins.                                                                          0.50 0.05  74.19                                                                            28400 60200                                                                             2.12                                         5   464 mins.                                                                          0.50 0.95  20.6                                                      6   935 mins                                                                           0.50 0.05  38.25                                                     __________________________________________________________________________

EXAMPLE 158 Heterogeneous 10 wt % Yttrium triflate on silica-aluminacatalyst preparation

25 g commercial silica-alumina pellets (Alfa cat #31269; 91% Al₂ O₃, 6%SiO₂) was placed in 250 mL water and the pH adjusted to 3 with aceticacid. The pellets were then treated in a manner identical to thatdescribed in Example 156 above.

EXAMPLE 159 Polymerization of THF over 10% Yttrium on Silica-AluminaPellets with Acetic Anhydride

All of the catalyst of Example 158, 10% yttrium triflate onsilica-alumina pellets (20.8 g) was charged in the reactor. Theapparatus was as described in Example 156. The following are theconditions under which polymer was collected, together with weight ofpolymer obtained and GPC analysis.

    __________________________________________________________________________             THF  ACA                                                                 Polymer.                                                                           Flow Rate                                                                          Flow Rate                                                                           Wt. Mn                                                    Fraction                                                                          Time (mL/min)                                                                           (mL/min)                                                                            (g) (PS STD.)                                                                          Mw  PD                                           __________________________________________________________________________    1   945 mins.                                                                          0.50 0.05  148.78                                                                             4370                                                                               8790                                                                             2.11                                         2   466 mins.                                                                          0.50 0.05  121.3                                                                             17000                                                                              33000                                                                             1.94                                         3   990 mins.                                                                          0.50 0.05  177.17                                                                            24800                                                                              48900                                                                             1.97                                         4   449 mins.                                                                          0.50 0.05  70.05                                                                             10000                                                                              26800                                                                             2.66                                         __________________________________________________________________________

EXAMPLE 160 Heterogeneous 10 wt % Zirconium triflate on alumina catalystpreparation.

25 g commercial alumina pellets (Al-3945, 3.2 mm dia.×3.2 mm)) wasplaced in 250 mL water and the pH adjusted to 3 with acetic acid. Thepellets were then treated in a manner identical to that described inExample 156 above except substituting zirconium triflate for yttriumtriflate.

EXAMPLE 161 Polymerization of THF over 10% Zirconium Triflate on AluminaPellets with Acetic Anhydride

All of the catalyst of Example 160, 10% zirconium triflate on aluminapellets (22.74 g), was charged in the reactor. The apparatus was asdescribed in Example 156. The following are the conditions under whichpolymer was collected, together with weight of polymer obtained.

    __________________________________________________________________________             THF  ACA                                                                 Polymer.                                                                           Flow Rate                                                                          Flow Rate                                                                           Wt. Mn                                                    Fraction                                                                          Time (mL/min)                                                                           (mL/min)                                                                            (g) (PS STD.)                                                                          Mw  PD                                           __________________________________________________________________________    1   928 mins.                                                                          0.50 0.05  247.97                                                                             9010                                                                              22500                                                                             2.51                                         2   498 mins.                                                                          0.50 0.05  75.00                                                                             10800                                                                              32500                                                                             2.99                                         3   948 mins.                                                                          0.50 0.05  164.13                                                                            29000                                                                              55800                                                                             1.92                                         4   482 mins.                                                                          0.50 0.05  58.91                                                                             45000                                                                              80700                                                                             1.79                                         5   896 mins.                                                                          0.50 0.05  201.15                                                                            41100                                                                              80600                                                                             1.96                                         __________________________________________________________________________

EXAMPLE 162 Preparation of La loaded zeolite HY for THF polymerization

10 g of zeolite LZY-82 (NH₄ ⁺ ion form of zeolite Y) was slurried into 1liter distilled water and the pH was adjusted to 4 with nitric acid.1.56 g lanthanum nitrate hexahydrate (calculated to give a final producthaving ˜5 wt % La) was added and the slurry stirred and warmed for 4hours. The stirring was stopped and the mixture left to sit overnight tocomplete the exchange. The solid was collected by-filtration and washedwith 1 liter distilled water then suction dried. The wet solid wasloaded into a horizontal tube furnace and fired as follows in flowingdry air (flow rate 200 mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. A small portionof the material was sent for x-ray diffraction analysis and showed thatthe zeolite crystallinity had been maintained during the ion-exchangeand calcination procedure and that there was no presence of a bulk La₂O₃ phase.

EXAMPLE 163 Polymerization of THF with Lanthanum Zeolite and AceticAnhydride

In a dry box, the lanthanum zeolite of Example 162 (2.00 g) was added toan oven dried 100 mL round bottom flask equipped with a stirring bar.The flask was sealed with a rubber septum and removed from the dry box.A nitrogen bleed was attached and THF (20.00 mL) and acetic anhydride(1.00 mL) were added. After stirring overnight the resulting materialwas diluted with THF (50 mL) and filtered. The resulting filtrate wasconcentrated at reduced pressure. The vicous liquid was dissolve in THF(50 mL) and dried over anhydrous NaHCO₃, filtered concentrated atreduced pressure and then dried under vacuum. Polymer yield: 3.86 g. GPCanalysis: Mn=969, Mw=5970, PD=6.17 (PS STD., bimodal distribution).

EXAMPLE 164 Preparation of 5% Y loaded zeolite HY for THF polymerization

10 g of zeolite LZY-82 (NH₄ ⁺ ion form of zeolite Y) was slurried into 1liter distilled water and the pH was adjusted to 4 with nitric acid.2.20 g yttrium nitrate pentahydrate (calculated to give a final producthaving ˜5 wt % Y) was added and the slurry stirred and warmed for 4hours. The stirring was stopped and the mixture left to sit overnight tocomplete the exchange. The solid was collected by filtration and washedwith 1 liter distilled water then suction dried. The wet solid wasloaded into a horizontal tube furnace and fired as follows in flowingdry air (flow rate 200 mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. A small portionof the material was sent for x-ray diffraction analysis and showed thatthe zeolite crystallinity had been maintained during the ion-exchangeand calcination procedure and that there was no presence of a bulk Y₂ O₃phase.

EXAMPLE 165 Polymerization of THF with 5% Yttrium Zeolite and AceticAnhydride

In a dry box, the yttrium zeolite of Example 164 (5.00 g) was added toan oven dried 100 mL round bottom flask equipped with a stirring bar.The flask was sealed with a rubber septum and removed from the dry box.A nitrogen bleed was attached and THF (20.00 mL) and acetic anhydride(1.00 mL) were added. After stirring overnight ether (50 mL was added tothe resulting polymerized solution. After filtering, ether (50 mL) andwater (25 mL) were added and the organic phase separated, concentratedat reduced pressure and then dried under vacuum. Polymer yield: 2.21 g.GPC analysis: Mn=840, Mw=4600, PD=5.48 (PS STD., bimodal distribution).

EXAMPLE 166 Polymerization of THF with 5% Yttrium Zeolite HY and AceticAnhydride

In a dry box, the 5% yttrium zeolite HY of Example 164 (10.00 g) wasadded to an oven dried 100 mL round bottom flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (20.00 mL) and aceticanhydride (1.00 mL) were added. After stirring overnight ether (50 mL)was added to the resulting polymerized solution. After filtering, ether(50 mL) and water (25 mL) were added and the organic phase separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 7.29 g. GPC analysis: Mn=1350, Mw=14800, PD=10.94 (PS STD.,bimodal distribution).

EXAMPLE 167 Preparation of 10 wt % Y loaded zeolite HY for THFpolymerization

50 g of zeolite LZY-82 (NH₄ ⁺ ion form of zeolite Y) was slurried into 1liter distilled water and the pH was adjusted to 4 with nitric acid.22.0 g yttrium nitrate pentahydrate (calculated to give a final producthaving ˜10 wt % Y) was added and the slurry stirred and warmed for 4hours. The stirring was stopped and the mixture left to sit overnight tocomplete the exchange. The solid was collected by filtration and washedwith 1 liter distilled water then suction dried. The wet solid wasloaded into a horizontal tube furnace and fired as follows in flowingdry air (flow rate 200 mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. A small portionof the material was sent for x-ray diffraction analysis and showed thatthe zeolite crystallinity had been maintained during the ion-exchangeand calcination procedure and that there was no presence of a bulk Y₂ O₃phase.

EXAMPLE 168 Polymerization of THF with 10 wt % Yttrium Zeolite HY andAcetic Anhydride

In a dry box, the 10% yttrium zeolite HY of Example 167 (10.00 g) wasadded to an oven dried 100 mL round bottom flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (20.00 mL) and aceticanhydride (1.00 mL) were added. After 4 hrs. ether (50 mL) was added tothe resulting polymerized solution. After filtering, the organic phasewas washed with 5% NaOH (10 mL), separated concentrated at reducedpressure then dried under vacuum. Polymer yield: 6.11 g. GPC analysis:Mn=690, Mw=4120, PD=10.94 (PS STD., bimodal distribution).

EXAMPLE 169

Preparation of Y loaded zeolite mordenite for THF polymerization

10 g of zeolite H-mordenite was slurried into 1 liter distilled waterand the pH was adjusted to 4 with nitric acid. 2.20 g yttrium nitratepentahydrate (calculated to give a final product having ˜5 wt % Y) wasadded and the slurry stirred and warmed for 4 hours. The stirring wasstopped and the mixture left to sit overnight to complete the exchange.The solid was collected by filtration and washed with 1 liter distilledwater then suction dried. The wet solid was loaded into a horizontaltube furnace and fired as follows in flowing dry air (flow rate 200mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. A small portionof the material was sent for x-ray diffraction analysis and showed thatthe zeolite crystallinity had been maintained during the ion-exchangeand calcination procedure and that there was no presence of a bulk Y₂ O₃phase.

EXAMPLE 170 Polymerization of THF with Yttrium Mordenite and AceticAnhydride

In a dry box, the yttrium mordenite of Example 169 (5.00 g) was added toan oven dried 100 mL round bottom flask equipped with a stirring bar.The flask was sealed with a rubber septum and removed from the dry box.A nitrogen bleed was attached and THF (20.00 mL) and acetic anhydride(1.00 mL) were added. After stirring overnight ether (50 mL) was addedto the resulting polymerized solution. After filtering, ether (50 mL)and water (25 mL) were added and the organic phase separated,concentrated at reduced pressure and then dried under vacuum. Polymeryield: 1.43 g. GPC analysis: Mn=6020, Mw=15500, PD=2.58 (PS STD.).

EXAMPLE 171 Preparation of ˜10 wt % Didymium loaded zeolite HY for THFpolymerization

50 g of zeolite LZY-82 (NH₄ ⁺ ion form of zeolite Y) was slurried into 1liter distilled water and the pH was adjusted to 4 with nitric acid. 10g didymium chloride was added and the slurry stirred and warmed for 1hour. The zeolite was recovered by filtration washed with 1 literdistilled water and then re-slurried into 1 liter fresh distilled water.Another 10 g didymium chloride was added and the pH adjusted to 4 withnitric acid and this slurry was stirred for 1 hour. The stirring wasstopped and the mixture left to sit overnight to complete the exchange.The solid was collected by filtration and washed with 1 liter distilledwater then suction dried. The wet solid was loaded into a horizontaltube furnace and fired as follows in flowing dry air (flow rate 200mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. The powder wasthen pressed to 10 tons and the resultant cake sieved through 10-20 meshto give granulated catalyst.

EXAMPLE 172 Polymerization of THF with 10% Didymium Zeolite HY andAcetic Anhydride

In a dry box, the 10% Didymium zeolite HY of Example 171 (10.00 g) wasadded to an oven dried 100 mL round bottom flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (20.00 mL) and aceticanhydride (1.00 mL) were added. After stirring overnight the polymerizedsolution was filtered, then ether (25 mL), THF (25 mL) and water (25 mL)were added the organic phase separated concentrated at reduced pressurethen dried under vacuum. Polymer yield: 7.56 g. GPC analysis: Mn=1010,Mw=7150, PD=7.08 (PS STD., bimodal distribution).

EXAMPLE 173 Preparation of 5 wt % Sc loaded zeolite HY for THFpolymerization

5 g of zeolite LZY-82 (NH₄ ⁺ ion form of zeolite Y) was slurried into 1liter distilled water and the pH was adjusted to 4 with nitric acid.1.44 g scandium chloride (calculated to give a final product having ˜5wt % Sc) was added and the slurry stirred and warmed for 4 hours. Thestirring was stopped and the mixture left to sit overnight to completethe exchange. The solid was collected by filtration and washed with 1liter distilled water then suction dried. The wet solid was loaded intoa horizontal tube Furnace and fired as follows in flowing dry air (flowrate 200 mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool powder was quickly transferred to a tightly capped sample vialin order to minimize exposure to atmospheric moisture. A small portionof the material was sent for x-ray diffraction analysis and showed thatthe zeolite crystallinity had been maintained during the ion-exchangeand calcination procedure and that there was no presence of a bulk Sc₂O₃ phase.

EXAMPLE 174 Polymerization of THF with 5% Scandium Zeolite HY and AceticAnhydride

In a dry box, the 5% scandium zeolite HY of Example 173 (3.94 g) wasadded to an oven dried 100 mL round bottom flask equipped with astirring bar. The flask was sealed with a rubber septum and removed fromthe dry box. A nitrogen bleed was attached and THF (20.00 mL) and aceticanhydride (1.00 mL) were added. After stirring overnight the polymerizedsolution was filtered, then ether (25 mL), THF (25 mL) and water (25 mL)were added the organic phase separated concentrated at reduced pressurethen dried under vacuum. Polymer yield: 4.48 g. GPC analysis: Mn=736,Mw=7890, PD=10.72 (PS STD., bimodal distribution).

EXAMPLE 175 Preparation of 10 wt % Y on zeolite NaY pellets

12.5 g yttrium nitrate pentahydrate was dissolved in 1 liter distilledwater and the pH adjusted to 4 with nitric acid. 25 g zeolite LZY-52(NaY) pellets (3 mm dia×3 mm) was added and the mixture allowed to sitovernight. The pellets were then filtered and washed with 1 literdistilled water and suction dried. The pellets were then calcined inflowing dry air (flow rate 200 mL/min):

Room temperature to 500° C. at 12° C./min.

Hold at 500° C. for 2 hours.

Cool to room temperature over 1 hour and collect white powder.

The cool pellets were quickly transferred to a tightly capped samplevial in order to minimize exposure to atmospheric moisture.

EXAMPLE 176 Polymerization of THF with 10% Yttrium Triflate on ZeoliteNaY Pellets and Acetic Anhydride

In a dry box, the 10% yttrium triflate on zeolite NaY pellets of Example175 (10.00 g) was added to an oven dried 100 mL round bottom flaskequipped with a stirring bar. The flask was sealed with a rubber septumand removed from the dry box. A nitrogen bleed was attached and THF(20.00 mL) and acetic anhydride (1.00 mL) were added. After stirring for1 hour THF (50 mL) the polymerized solution then filtered. The filtratewas washed with water (25 mL), then ether (50 mL) was added. The organicphase was separated concentrated at reduced pressure then dried undervacuum. Polymer yield: 0.700 g. GPC analysis: Mn=18800, Mw=27100,PD=1.44 (PS STD.).

EXAMPLE 177 Preparation of Yttrium triflate supported on aluminaderivatized with diethylmalonate

95 mL ethanol and 5 mL water were mixed and the pH adjusted to 5 withacetic acid. 2 g DETM was added and the mix stirred for 5 minutes. 10 gγ-alumina was added and the slurry stirred further 3 min. The solid wasallowed to settle and the supernatant liquid decanted. The recoveredsolid was then washed with two portions of 25 mL ethanol and suctiondried. The solid was finally dried in flowing nitrogen (200 mu/min) byheating to 110° C. and holding at that temperature for 1 hour. Thecooled powder was immediately transferred to a nitrogen glove box.

Under a dry nitrogen atmosphere inside a glove box, 0.5 g yttriumtriflate was dissolved in 25 mL acetonitrile and 5 g of the aluminapowder prepared above was added. The slurry was stirred for 1 hour andthen filtered, rinsed with 25 mL acetonitrile and suction dried. Thepowder was then pumped to dryness in vacuum and stored under nitrogen.

EXAMPLE 178 Polymerization of THF with Yttrium Triflate Supported onAlumina Derivatized with Diethyl Malonate

In a dry box, the yttrium triflate supported on diethylmalonatederivatized alumina of Example 177 (5.00 g) was weighed in an oven dried100 mL RB flask. The flask was sealed with a rubber septum and removedfrom the dry box. A nitrogen purge was attached and THF (15.00 mL) andacetic anhydride (2.00 mL) added via syringe. After 360 minutes thepolymerization was terminated by decanting, followed by concentration atreduced pressure and then drying under vacuum. Polymer yield: 2.53 g.GPC analysis: Mn=8300, Mw=20900, PD=2.52 (PS STD.).

EXAMPLE 179 Preparation ofbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumsupported on silica derivatized with DETM

95 mL ethanol and 5 mL water were mixed and the pH adjusted to 5 withacetic acid. 2 g DETM was added and the mix stirred for 5 minutes. 10 gsilica was added and the slurry stirred a further 3 mins. The solid wasallowed to settle and the supernatant liquid decanted. The recoveredsolid was then washed with two portions of 25 mL ethanol and suctiondried. The solid was finally dried in flowing nitrogen (200 mL/min) byheating to 110° C. and holding at that temperature for 1 hour. Thecooled powder was immediately transferred to a nitrogen glove box.

Under a dry nitrogen atmosphere inside a glove box, 0.5 gbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumwas dissolved in 25 mL acetonitrile and 5 g of the silica powder wasadded. The slurry was stirred for 1 hour and then filtered, rinsed with25 mL acetonitrile and suction dried. The powder was then pumped todryness in vacuum and stored under nitrogen.

EXAMPLE 180 Polymerization of THF withBis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)ZirconiumSupported on Silica Derivatized with Diethyl Malonate

In a dry box, thebis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethane-sulfonato)zirconiumsupported on silica of Example 179 (5.00 g) was weighed in an oven dried100 mL RB flask. The flask was sealed with a rubber septum and removedfrom the dry box. A nitrogen purge was attached and THF (15.00 mL) andacetic anhydride (2.00 mL) were added via syringe. After 360 minutes thepolymerization was terminated by decanting, followed by concentration atreduced pressure and then drying under vacuum. Polymer yield: 2.06 g.GPC analysis: Mn=7620, Mw=19000, PD=2.29 (PS STD.).

EXAMPLE 181 Preparation ofbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumsupported on alumina derivatized with DETM

95 mL ethanol and 5 mL water were mixed and the pH adjusted to 5 withacetic acid. 2 g DETM was added and the mix stirred for 5 minutes. 10 g% λ-alumina was added and the slurry stirred a further 3 mins. The solidwas allowed to settle and the supernatant liquid decanted. The recoveredsolid was then washed with two portions of 25 mL ethanol and suctiondried. The solid was finally dried in flowing nitrogen (200 mL/min) byheating to 110° C. and holding at that temperature for 1 hour. Thecooled powder was immediately transferred to a nitrogen glove box.

Under a dry nitrogen atmosphere inside a glove box, 0.5 gbis(n-cyclopentadienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumwas dissolved in 25 mL acetonitrile and 5 g of the alumina powderprepared above was added. The slurry was stirred for 1 hour and thenfiltered, rinsed with 25 mL acetonitrile and suction dried. The powderwas then pumped to dryness in vacuum and stored under nitrogen.

EXAMPLE 182 Polymerization of THE withBis(n-cyclopentdienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)ZirconiumSupported on Alumina Derivatized with Diethyl Malonate

In a dry box, thebis(n-cyclopentdienyl)tetrahydrofuran-bis(trifluoromethanesulfonato)zirconiumsupported on alumina of Example 181 (5.00 g) was weighed in an ovendried 100 mL RB flask. The flask was sealed with a rubber septum andremoved from the dry box. A nitrogen purge was attached and THF (15.00mL) and acetic anhydride (2.00 mL) added via syringe. After 360 minutesthe polymerization was terminated by decanting, followed byconcentration at reduced pressure and then drying under vacuum. Polymeryield: 1.99 g. GPC analysis: Mn=9600, Mw=25800, PD=2.69 (PS STD.).

EXAMPLE 183 Preparation of ˜10 wt % Ytterbium triflate supported onsilica-alumina

50 g silica-alumina pellets (3.2 mm dia.×3.2 mm) were placed in 250 mLdistilled water. The pH was adjusted to 3 with acetic acid and theslurry was stirred for 15 mins. The pellets were collected by filtrationand then added to a solution of 190 mL ethanol, 10 mL water in which thepH was adjusted to 5 with acetic acid and then 5 g DETM was added.Stirred for 30 min and then the supernatant liquid was decanted. Thepellets were washed with two portions of 25 mL ethanol and then suctiondried prior to drying in flowing nitrogen (200 mL/min) at 110° C. for 1hour. The pellets were then transferred to a nitrogen glove box.

Inside the glove box 10 g ytterbium triflate was dissolved in 100 mL dryacetonitrile and this solution was added to the dry pellets. The slurrythen sat overnight under nitrogen before being evaporated to dryness.The recovered solid was washed with three 25 mL portions of dryacetonitrile, suction dried and then dried in flowing nitrogen to 110°C. for 1 hour. The dry pellets were stored under nitrogen in a glovebox.

EXAMPLE 184 Depolymerization of Polytetrahydrofuran (Terathane® 1000)with 10% Ytterbium Triflate Supported on Silica-Alumina

Polytetrahydrofuran with hydroxyl ends (Terathane® 1000, 300 g, Aldrich)and the 10% ytterbium triflate supported on silica-alumina of Example183 (10 g) were placed in a 500 mL three neck flask equipped with astirring bar, Vigreaux column (12") and a fractional distillation head.A nitrogen purge was attached and all other openings were glassstoppered.

The resulting mixture was heated with an oil bath and the resultingwater clear distillate fractions collected as follows:

    ______________________________________                                               Oil Bath  Rxn Temp.   Head Temp                                                                             Weight                                   Fraction                                                                             Temp (°C.)                                                                       (°C.)                                                                              (°C.)                                                                          (g)                                      ______________________________________                                        1      180       152         64      70.72                                    2      198       163         66      112.0                                    3      196       124         66      59.00                                    4      202       149         66      55.00                                    ______________________________________                                         Total weight of distillate collected: 296.72 g                                % Yield (Recovery): 98.9%                                                     GC analyses of the various fractions confirm the product to be THF       

COMPARATIVE EXAMPLE 1

In a dry box, zeolite HY (1.00 g) was added to an oven dry 100 mL RBflask equipped with a stirring bar. The flask was sealed with a rubberseptum and removed from the dry box. After the attachment of a nitrogenbleed THF (20.00 mL) was added by syringe. After 45 minutes aceticanhydride (1.00 mL) was added. After filtering off the zeolite catalystand concentration of the filtrate, no polymer was obtained.

EXAMPLE 185 Polymerization of THF with Ytterbium Triflate and3-Methyladipic Acid

In a dry box, ytterbium triflate (10.0 g) and 3-methyladipic acid (5.0g) were added to each of three separate oven dried 100 mL RB flasksequipped with stirring bars. The flasks were sealed with rubber septaand then removed from the dry box. Nitrogen bleeds were attached and THF(20.0 mL) was added to each flask. After 2,4, and 6 hours apolymerization was terminated via the addition of water. (25 mL), ether(25 mL) and THF (50 mL). The resulting organic phases were separated,concentrated at reduced pressure and then dried under vacuum. Polymeryields and GPC analysis:

    ______________________________________                                                                Mn                                                    Polymerization Time                                                                       Polymer Yield (g)                                                                         (PS* STD) Mw    PD                                    ______________________________________                                        2 hrs.      2.96        8630      13800 1.61                                  4 hrs.      3.15        8170      13300 1.63                                  6 hrs.      4.79        7230      12600 1.75                                  ______________________________________                                         *Polystyrene standard                                                    

EXAMPLE 186 Polymerization of THF with Ytterbium Triflate and AdipicAcid

In a dry box, ytterbium triflate (5.0 g) and adipic acid (1.21 g) wereadded to an oven dried 100 mL RB flask equipped with a stirring bar. Theflask was sealed with rubber septum and then removed from the dry box, anitrogen bleed was attached and THF (20.0 mL) added. After 60 minutesthe polymerization was terminated via the addition of water (25 mL),ether (25 mL) and THF (50 mL). The resulting organic phase wasseparated, concentrated at reduced pressure and then dried under vacuum.Polymer yield: 7.65 g. GPC analysis (PS STD.): Mn=14000, Mw=39300,PD=2.80, IR analysis (CHCl₃, cm⁻¹): 2860, 1727 (C═O), 1370, 1100.

EXAMPLE 187 Polymerization of THF with Ytterbium Triflate and MaleicAcid

In a dry box, ytterbium triflate (5.0 g) and maleic acid (1.9 g) wereadded to an oven dried 100 mL RB flask equipped with a stirring bar. Theflask was sealed with rubber septum and then removed from the dry box, anitrogen bleed was attached and THF (20.0 mL) added. After 60 minutesthe polymerization was terminated via the addition of water (25 mL),ether (25 mL) and THF (50 mL). The resulting organic phase wasseparated, concentrated at reduced pressure and then dried under vacuum.Polymer yield: 3.98 g. GPC analysis (PS STD): Mn=8950, Mw=16800,PD=1.88.

EXAMPLE 188 Polymerization of THF with Ytterbium Triflate andIsophthalic Acid

In a dry box, ytterbium triflate (5.0 g) and isophthalic acid (2.76 g)were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with rubber septum and then removed from thedry box, a nitrogen bleed was attached and THF (20.0 mL) added. After 60minutes the polymerization was terminated via the addition of water. Thepolymer was dissolved in methylene chloride. The resulting organicsolution was washed with water (2×200 mL), then concentrated at reducedpressure and then dried under vacuum. Polymer yield: 12.24 g. GPCanalysis (PS STD): Mn=258000, Mw=559000, PD=2.16.

EXAMPLE 189 Polymerization of THF with Ytterbium Triflate andTerephthalic Acid

In a dry box, ytterbium triflate (5.0 g) and terephthalic acid (2.76 g)were added to an oven dried 100 mL RB flask equipped with a stirringbar. The flask was sealed with rubber septum and then removed from thedry box, a nitrogen bleed was attached and THF (20.0 mL) was added.After 60 minutes the polymerization was terminated via the addition ofwater. The polymer was dissolved in methylene chloride. The resultingorganic solution was washed with water (2×200 mL), then concentrated atreduced pressure and then dried under vacuum. Polymer yield: 3.66 g. GPCanalysis (PS STD): Mn=308000, Mw=744000, PD=2.42.

EXAMPLE 190 Polymerization of THF with Ytterbium Triflate and A ##STR7##

In a dry box, ytterbium triflate (5.0 g) and A (1.5 g) were added to anoven dried 100 mL RB flask equipped with a stirring bar. The flask wassealed with rubber septum and then removed from the dry box, a nitrogenbleed was attached and THF (20.0 mL) added. After 120 minutes thepolymerization was terminated via the addition of water, THF and ether.The resulting separated organic solution was washed with sodiumbicarbonate (2×25 mL), then concentrated at reduced pressure and driedunder vacuum. Polymer yield: 2.37 g.

EXAMPLE 191 Polymerization of THF with Ytterbium Triflate and A

In a dry box, ytterbium triflate (5.0 g) and A (0.5 g) were added to anoven dried 100 mL RB flask equipped with a stirring bar. The flask wassealed with rubber septum and then removed from the dry box, a nitrogenbleed was attached and THF (20.0 mL) was added. After 60 minutes thepolymerization was terminated via the addition of water, THF and ether.The resulting separated organic solution was washed with sodiumbicarbonate (2×25 mL), then concentrated at reduced pressure and thendried under vacuum. Polymer yield: 1.97 g. GPC analysis (PS STD):Mn=72200, Mw=173000, PD=2.39.

EXAMPLE 192 Polymerization of THF with Ytterbium Triflate and B ##STR8##

In a dry box, ytterbium triflate (5.0 g) and B (1.5 g) were added to anoven dried 100 mL RB flask equipped with a stirring bar. The flask wassealed with rubber septum and then removed from the dry box, a nitrogenbleed was attached and THF (20.0 mL) added. After 120 minutes thepolymerization was terminated via the addition of water, THF and ether.The resulting separated organic solution was washed with sodiumbicarbonate (2×25 mL), then concentrated at reduced pressure and thendried under vacuum. Polymer yield: 8.49 g. GPC analysis (PS STD):Mn=127000, Mw=341000, PD=2.67.

EXAMPLE 193 Polymerization of THF with Ytterbium Triflate and1,2,4-Benzenetricarboxylic Acid

In a dry box, ytterbium triflate (5.0 g) and 1,2,4-benzenetricarboxylicacid (2.0 g) were added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with rubber septum and then removedfrom the dry box, a nitrogen bleed was attached and THF (20.0 mL) added.After 21 hours the polymerization was terminated via the addition ofwater, THF and ether. The resulting separated organic solution waswashed with sodium bicarbonate (25 mL) upon which a gelatinous materialresulted. HCl was then added and the organic phase separated, thenconcentrated at reduced pressure and finally dried under vacuum. Polymeryield: 8.91 g. GPC analysis (PS STD): Mn=100000, Mw=227000, PD=2.26.

EXAMPLE 194 Polymerization of THF with Ytterbium Triflate and1,1'-Ethylenebis(5-oxo-3-pyrrolidecarboxylic Acid)

In a dry box, ytterbium triflate (5.0 g) and1,1'-ethylenebis(5-oxo-3-pyrrolidecarboxylic acid) (1.0 g) were added toan oven dried 100 mL RB flask equipped with a stirring bar. The flaskwas sealed with rubber septum and then removed from the dry box, anitrogen bleed was attached and THF (20.0 mL) added. After 3 hours thepolymerization was terminated via the addition of water, THF and ether.The resulting separated organic solution was washed with sodiumbicarbonate then the organic phase separated, concentrated at reducedpressure and finally dried under vacuum. Polymer yield: 5.21 g. GPCanalysis (PS STD): Mn=73200, Mw=194000, PD=2.65.

EXAMPLE 195 Polymerization of THF with Ytterbium Triflate andIsophthalic Acid and Terephthalic Acid

In a dry box, ytterbium triflate (5.0 g), terephthalic acid (2.00 g) andisophthalic acid (0.5 g) were added to an oven dried 100 mL RB flaskequipped with a stirring bar. The flask was sealed with rubber septumand then removed from the dry box, a nitrogen bleed was attached and THF(20.0 mL) added. After stirring overnight the polymerization wasterminated via the addition of water. The polymer was dissolved inmethylene chloride. The resulting organic solution was washed with water(2×200 mL), then concentrated at reduced pressure and then dried undervacuum. Polymer yield: 7.38 g. GPC analysis (PS STD): Mn=42000,Mw=138000, PD=3.30.

EXAMPLE 196 Polymerization of THF with Ytterbium Triflate andN-Acetyl-L-glutamic Acid

In a dry box, ytterbium triflate (15.0 g) and N-acetyl-L-glutamic acid(1.0 g) were added to an oven dried 100 mL RB flask equipped with astirring bar. The flask was sealed with rubber septum and then removedfrom the dry box, a nitrogen bleed was attached and THF (20.0 mL) added.After stirring overnight the polymerization was terminated via theaddition of water, THF and ether. The resulting organic solution waswashed with water, then concentrated at reduced pressure and then driedunder vacuum. Polymer yield: 2.82 g. GPC analysis (PS STD): Mn=16600,Mw=80500, PD=4.83.

EXPERIMENT 1 Preparation of (HOCOPh--NHC(O)NH--Ph)₂ --CH₂

In a dry box, MDI (25.0 g) was weighed into a 500 mL RB flask equippedwith a stirrer, dimethylacetamide (DMAC, 75 mL) was then added. Asolution of 4-aminobenzoic acid (27.8 g) in DMAC (25 mL) was slowlyadded to the stirred MDI/DMAC solution. The reaction was allowed to stirovernight, then the reaction mixture was poured into diethyl ether. Theresulting precipitate was filtered and dried under vacuum at 100° C. Inthis compound all phenyl rings are para substituted.

EXAMPLE 197 Polymerization of THF with (HO₂ CPh--NHC(O)NH--Ph)₂ --CH₂and Ytterbium Triflate

In a dry box, ytterbium triflate (5.00 g) and (HO₂ CPh--NHC(O)NH--Ph)₂--CH₂ (1.0 g) were added to an oven dried 100 mL RB flask equipped witha stirring bar. The flask was sealed with a rubber septum and removedfrom the dry box. After the attachment of a nitrogen bleed THF (20.00mL) was added via syringe. After 18 hrs. the resulting solid mass wasdissolved in THF (˜800 mL) and water (˜10 mL). The resulting mixture wasfiltered through Celite and then concentrated at reduced pressure to˜200 mL, then poured into a Waring blender containing water (˜500 mL).The resulting precipitated polymer was recovered via filtration anddried under vacuum affording 10.30 g of white material.

EXAMPLE 198 Polymerization of THF/3-Me-THF with (HO₂ CPh--NHC(O)NH--Ph)₂--CH₂ and Ytterbium Triflate

In a dry box, ytterbium triflate (5.00 g) and (HO₂ CPh--NHC(O)NH--Ph)₂--CH₂ (1.0 g) were added to an oven dried 100 mL RB flask equipped witha stirring bar. The flask was sealed with a rubber septum and removedfrom the dry box. After the attachment of a nitrogen bleed THF (15.00mL) and 3-Me-THF (5.0 mL) were added via syringe. After 18 hrs. theresulting solid mass was dissolved in THF (˜800 mL) and water (˜10 mL).The resulting mixture was filtered through Celite and then concentratedat reduced pressure to ˜200 mL, then poured into a Waring blendercontaining water (˜500 mL). The resulting precipitated polymer wasrecovered via filtration and dried under vacuum affording 7.38 g ofwhite material.

EXPERIMENT 2 Preparation of (HO₂ CC(CH₃)₂ CH₂ O--C(O)NH--Ph)₂ --CH₂

In a dry box, MDI (25.0 g) was weighed into a 500 mL RB flask equippedwith a stirrer, dimethylacetamide (DMAC, 70 mL) was then added followedby hydroxypivalic acid (23.8 g). The reaction was allowed to stirovernight, then the reaction mixture was poured into water. Theresulting precipitate was filtered and dried under vacuum at 100° C.,affording 46.28 g (94.84%) of product. All phenyl rings in this compoundare para substituted.

EXAMPLE 199 Polymerization of THF with (HO₂ CC(CH₃)₂ CH₂ O--C(O)NH--Ph)₂--CH₂ and Ytterbium Triflate

In a dry box, ytterbium triflate (10.00 g) and (HO₂ CC(CH₃)₂ CH₂O--C(O)NH--Ph)₂ --CH₂ (1.0 g) were added to an oven dried 100 mL RBflask equipped with a stirring bar. The flask was sealed with a rubberseptum and removed from the dry box. After the attachment of a nitrogenbleed THF (20.00 mL) was added via syringe. After 16 hrs. the resultingsolid mass was repeatedly washed with water, then dried under vacuumaffording 6.40 g of white material. NMR and GPC analysis showed theproduct to be contaminated with a small amount of the starting diacid.

What is claimed is:
 1. A process for the polymerization of cyclicethers, comprising, contacting, at a temperature of about -80° C. toabout 130° C., one or more tetrahydrofurans, oxepanes, 1,3-dioxolanes or1,3,5-trioxanes with a catalytic system consisting essentially of acompound of the formula MZ_(s).Q_(t), and an accelerator selected fromthe group consisting of carboxylic acids whose pKa in water is less than6, carboxylic anhydrides and acyl halides, wherein:M is a metal selectedfrom the group consisting of niobium, tungsten, yttrium, the rare earthmetals, zirconium, hafnium, molybdenum, tantalum, rhenium, ruthenium,osmium, rhodium, iridium, palladium, platinum, gold, cadmium, germanium,tin, lead, arsenic, antimony and bismuth; at least one of Z is an anionof the formula R⁵ SO₃ ⁻, wherein R⁵ is perfluoroalkyl containing 1 to 12carbon atoms or part of a fluorinated polymer wherein the carbon atomsalpha and beta to the sulfonate group are together bonded to at leastfour fluorine atoms, or tetraphenylborate, and the remainder of Z is oxoor one or more monovalent anions; s is 2 when M is rhodium, iridium,palladium, platinum, or cadmium; s is 3 when M is yttrium, a rare earthmetal, arsenic, antimony, bismuth, gold, ruthenium, or osmium; s is 4when M is zirconium, hafnium, molybdenum, germanium, tin, or lead; s is5 when M is rhenium, niobium or tantalum; s is 6 when M is tungsten; Qis a neutral ligand; t is 0 or an integer of 1 to 6; and provided thateach oxo group present as part of Z is considered to account for two ofs.
 2. The process as recited in claim 1 wherein M is a metal selectedfrom the group consisting of niobium, tungsten, mischmetall, yttrium, arare earth metal, zirconium, hafnium, molybdenum, tantalum, rhenium,ruthenium, osmium, rhodium, iridium, palladium, platinum, gold, cadmium,germanium, tin, lead, arsenic, antimony and bismuth.
 3. The process asrecited in claim 2 wherein said cyclic ether comprises the formula##STR9## wherein: each R¹, R², R³ and R⁴ is independently hydrogen orhydrocarbyl containing 1 to 20 carbon atoms; andn is 2 or
 4. 4. Theprocess as recited in claim 3 wherein n is 2 and R¹, R⁴ and all of R²and R³ are hydrogen.
 5. The process as recited in claim 4 wherein M isyttrium, a rare earth metal, zirconium, hafnium, niobium, tantalum,molybdenum, tungsten, rhenium, ruthenium, palladium, gold, tin, bismuthor mischmetall.
 6. The process as recited in claim 3 wherein n is 2 andR¹ and R⁴ are each hydrogen, one of R² is hydrogen, the other R² ismethyl, and both R³ are hydrogen.
 7. The process as recited in claim 2wherein R⁵ is trifluoromethyl or perfluoroalkyl.
 8. The process asrecited in claim 1 wherein said carboxylic acid is trifluoroacetic acid,formic, acetic, cyanoacetic, nitropropionic, acrylic or methacrylicacid.
 9. The process as recited in claim 1 wherein said carboxylicanhydride is acetic anhydride or trifluoroacetic anhydride.
 10. Aprocess for the polymerization of cyclic ethers, comprising, contacting,at a temperature of about -80° C. to about 130° C., one or moreoxiranes, oxetanes, tetrahydrofurans, oxepanes, 1,3-dioxolanes or1,3,5-trioxanes with a zeolite which contains a metal cation selectedfrom the group consisting of silver, niobium, tungsten, yttrium, therare earth metals, molybdenum, tantalum, rhenium, ruthenium, osmium,rhodium, iridium, palladium, platinum, gold, cadmium, germanium, tin,lead, arsenic, antimony and bismuth; and an accelerator selected fromthe group consisting of carboxylic anhydrides, acyl halides andcarboxylic acids whose pKa in water is less than about
 6. 11. Theprocess as recited in claim 10 wherein said cyclic ether is one or moretetrahydrofurans, oxepanes, 1,3-dioxolanes, or 1,3,5-trioxanes.
 12. Theprocess as recited in claim 11 wherein said cyclic ether comprises theformula: ##STR10## wherein n is 2 or 4, and each R¹, R², R³ and R⁴ isindependently hydrogen or hydrocarbyl containing 1 to 20 carbon atoms.13. The process as recited in claim 12 wherein all of R¹, R², R³ and R⁴are hydrogen.
 14. The process as recited in claim 12 wherein n is 2; andwherein R¹, one of R², both of R³ and R⁴ are hydrogen and the remainingR² is alkyl containing 1-4 carbon atoms.
 15. The process as recited inclaim 10 wherein said metal cation is yttrium, a rare earth metal,zirconium, hafnium, mischmetall, niobium, tantalum, molybdenum,tungsten, rhenium, ruthenium, palladium, gold, tin or bismuth.
 16. Theprocess as recited in claim 15 wherein said metal cation is yttrium,ytterbium, dysprosium, erbium, neodymium, lanthanum, mischmetall, orzirconium.
 17. The process as recited in claim 10 wherein saidaccelerator is a carboxylic acid whose pKa in water is about 6 or less.18. The process as recited in claim 17 wherein said carboxylic acid isselected from the group consisting of formic, acetic, trifluoroacetic,acrylic, methacrylic, cyanoacetic, nitropropionic, and nitrobenzoic. 19.A process for the polymerization of cyclic ethers, comprising,contacting, at a temperature of about -80° C. to about 130° C., one ormore oxiranes, oxetanes, tetrahydrofurans, oxepanes, 1,3-dioxolanes, or1,3,5-trioxanes; with a catalytic system consisting essentially of aheterogeneous catalyst containing a metal perfluoroalkylsulfonateattached to the surface of said catalyst though said metal, and anaccelerator; said metal selected from the group consisting of niobium,tungsten, yttrium, the rare earth metals, zirconium, hafnium,molybdenum, tantalum, rhenium, ruthenium, osmium, rhodium, iridium,palladium, platinum, gold, cadmium, germanium, tin, lead, arsenic,antimony and bismuth; said accelerator selected from the groupconsisting of carboxylic anhydrides, acyl halides, and carboxylic acidswhose pKa in water is less than about
 6. 20. The process as recited inclaim 19 wherein said cyclic ether is one or more of tetrahydrofurans,oxepanes, 1,3-dioxolanes, or 1,3,5-trioxanes.
 21. The process as recitedin claim 20 wherein said cyclic ether comprises the formula: ##STR11##wherein n is 2 or 4, and each R¹, R², R³ and R⁴ is independentlyhydrogen or hydrocarbyl containing 1 to 20 carbon atoms.
 22. The processas recited in claim 21 wherein all of R¹, R², R³ and R⁴ are hydrogen.23. The process as recited in claim 21 wherein n is 2; and wherein R¹,one of R², both of R³ and R⁴ are hydrogen and the remaining R² is alkylcontaining 1-4 carbon atoms.
 24. The process as recited in claim 19wherein said metal cation is yttrium, a rare earth metal, zirconium,hafnium, mischmetall, niobium, tantalum, molybdenum, tungsten, rhenium,ruthenium, palladium, gold, tin or bismuth.
 25. The process as recitedin claim 24 wherein said metal cation is yttrium, ytterbium, dysprosium,erbium, neodymium, lanthanum, mischmetall, or zirconium.
 26. The processas recited in claim 19 wherein said accelerator is a carboxylic acidwhose pKa in water is about 6 or less.
 27. The process as recited inclaim 19 wherein said heterogeneous catalyst support is alumina, silica,silica-aluminate, carbon or zirconia.
 28. A process for the productionof poly(ether-esters), comprising, contacting, at a temperature of about-80° C. to about 130° C., a tetrahydrofuran with a polycarboxylic acidof the formula A(CO₂ H)_(x) and a catalyst of the formula MZ_(s).Qt,wherein:M is a metal selected from the group consisting of tungsten,niobium, yttrium, a rare earth metal zirconium, hafnium, molybdenum,tantalum, rhenium, ruthenium, osmium, rhodium, iridium, palladium,platinum, silver, gold, cadmium, germanium, tin, lead, arsenic, antimonyand bismuth; Z is an anion of the formula R⁵ SO₃ ⁻, wherein R⁵ isperfluoroalkyl containing 1 to 12 carbon atoms or part of a fluorinatedgroup wherein the carbon atoms alpha and beta to the sulfonate group aretogether bonded to at least four fluorine atoms; s is 1 when M issilver; s is 2 when M is rhodium, iridium, palladium, platinum, orcadmium ; s is 3 when M is yttrium, a rare earth metal, arsenic,antimony, bismuth, gold, ruthenium, or osmium; s is 4 when M iszirconium, hafnium, molybdenum, germanium, tin, or lead; s is 5 when Mis rhenium, niobium or tantalum; s is 6 when M is tungsten; Q is aneutral ligand; t is 0 or an integer of 1 to 6; and each A isindependently an organic radical having x free valencies; each x isindependently 2, 3, 4, 5 or 6; and provided that:A is bound to carboxylgroups through a carbon atom; said polycarboxylic acid has a pKa ofabout 6 or less; said polycarboxylic acid does not by itself catalyzepolymerization of the tetrahydrofuran; and the ratio of equivalents ofcarboxyl groups of said polycarboxylic acid to moles of said catalyst isless than
 6. 29. The process of claim 28 wherein x is
 2. 30. The processas recited in claim 28 wherein M is a metal selected from the groupconsisting of yttrium, a rare earth metal zirconium, hafnium,molybdenum, tantalum, rhenium, ruthenium, osmium, rhodium, iridium,palladium, platinum, silver, gold, cadmium, germanium, tin, lead,arsenic, antimony and bismuth.
 31. The process as recited in claim 28wherein the tetrahydrofuran is of Formula I, wherein R¹, R⁴, and all ofR² and R³ are hydrogen ##STR12##
 32. The process as recited in claim 28wherein the tetrahydrofuran is of Formula I, wherein R¹ and R⁴ arehydrogen, one of R² is hydrogen, the other R² is methyl, and both ofcare hydrogen ##STR13##
 33. The process as recited in claim 28 whereinR⁵ is trifluoromethyl.
 34. The process as recited in claim 28 wherein Ais tetramethylene, p-phenylene, or m-phenylene.
 35. The process asrecited in claim 28 wherein A contains one or more of imide, ester,amide, urethane or urea.
 36. The process as recited in claim 28 whereinthe tetrahydrofuran is of Formula I wherein all of R¹, R², R³ and R⁴ areindependently hydrogen or a C₁ to C₂₀ hydrocarbyl ##STR14##